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Printed in Great Britain. 


IT has been a great satisfaction to me to carry out the 
wish of my dear friend Elie Metchnikoff, and arrange 
for the production of an English translation of his 
biography. The account of his life and work written 
by Olga Metchnikoff is a remarkable and beautiful 
record of the development and activities of a great 
discoverer. It is remarkable because it is seldom 
that one who undertakes such a task has had so 
constant a share in, and so complete a knowledge and 
understanding of, the life portrayed as in the present 
case : seldom that the intimate thought and mental 
" adventure " of a discoverer presents so clear and 
consistent a history. It is beautiful because it is 
put before us with perfect candour and simplicity 
guided by rare intelligence and inspired by deep 
affection. Madame Metchnikoff has drawn the 
picture of the development of a single-minded 
character absolutely and tenaciously devoted to a 
high purpose the improvement of human life. It 
is a story of " struggles and adventures," but they 
are wholly in the field of the investigation of Nature. 
We read here little or nothing of the quest for personal 
advancement, for fortune or official position. These 
things had no attraction for Metchnikoff. He left 


Russia and took an unpaid post in Paris in order to 
have a place to work in. He had many devoted 
friends in whose company he sought refreshment and 
relaxation, but all his immense energy and industry 
were concentrated on the development and establish- 
ment of his great biological theory of " Phagocytosis " 
and its outcome, the philosophy of life called by him 
" Orthobiosis." This volume tells truly of a simple 
life a life in which the social incidents which fill so 
large a space in most lives were either non-existent 
or unnoticed because, by the side of the great purpose 
which dominated MetchnikofFs every thought and 
action namely, the advancement of Science lie was 
not touched by them. He was affectionate, kind- 
hearted, and truly considerate of others, but was, in 
a way which is traceable to his racial origin, a practical 
idealist concentrating his whole strength and reason 
on the realisation of what he held to be the highest 

I had as an eager reader of memoirs on bio- 
logical subjects become acquainted with Metchnikoff's 
earliest publications in 1865, when he was twenty 
years of age and I two years younger. I wrote short 
accounts of them, as they appeared, for a chronicle 
of progress in the Quarterly Journal of Microscopical 
Science, then edited by my father. Those on a 
European Land Planarian, on the development of 
Myzostomum (the parasite of the Feather-Star), on 
Apsilus, a strange new kind of wheel-animalcule, and 
his protest against Rudolf Leuckart's treatment of 
him in the matter of his important discoveries con- 


cerning the Frog's lung-worm Ascaris nigrovenosa 
remain in my memory, and later, in 1872, I was 
especially struck by his important demonstration of 
the true mode of development of the gastrula of the 
calcareous sponges in correction of Professor Ernst 
Haeckel. Many other papers of his became known 
to me, until in 1881 he published his first observa- 
tions on Intracellular Digestion in Lower Animals, 
which was the starting-point of his life's work on 
" Phagocytosis," to which all his subsequent re- 
searches during thirty-five years were exclusively 

In L888 I was introduced by my friend Lauder 
Brunton to the great Pasteur, and called on him at 
his laboratory in the rue d'Ulm. There I met 
Metchnikoff, only lately arrived from Russia, and 
welcomed as one of his staff by Pasteur. The next 
year, 1889, Pasteur was installed in the new " Institut 
Pasteur " in the rue Dutot, and I met Metchnikoff 
there in his new quarters. Pasteur's assistants were 
carrying on daily his system of inoculation against 
rabies, and many British subjects were amongst those 
treated. I persuaded the Lord Mayor of that year, 
Sir James Whitehead, to visit the Pasteur Institute 
with a view to taking steps to make some recognition 
of the services rendered by Pasteur to our fellow- 
countrymen in treating over two hundred of them 
threatened with hydrophobia. Sir James called a 
meeting on July 1, 1889, at the Mansion House, and 
placed the management of it in my hands. As a 
result we obtained subscriptions to a fund which 


enabled us to assist many poor British subjects to 
visit Paris for the purpose of undergoing M. Pasteur's 
treatment, to make a donation of 30,000 francs to the 
Pasteur Institute, and to initiate with a sum of 
300 the formation of a fund for the purpose of 
establishing an Institute in London similar in purpose 
and character to the Institut Pasteur. That initial 
fund has step by step received generous additions and 
given us the " Lister Institute " on Chelsea Embank- 
ment possessed of buildings, site, and capital valued 
at more than 300,000. 

After 1889 it was rare for a year to pass without 
my visiting Paris both in spring and summer, and 
seeing a great deal of Metchnikoff and his friends 
Roux, Duclaux, Laveran, and the great master of the 
Pastorians, who died in 1895. Metchnikoff took me 
to his home and cemented his friendship with me by 
bringing to me that of his gifted and devoted wife. 

Madame Metchnikoff had when a schoolgirl studied 
zoology under her future husband at Odessa, and now 
was able to give serious help in some of his researches. 
She published some experimental investigation on the 
sterilisation of the alimentary canal of tadpoles and 
some other researches, and having a thorough know- 
ledge of English, which Elie did not possess, she helped 
him in reading and translating from that language. 
But her chief talents were in the arts of painting and 
sculpture, and when they purchased their country 
house at Sevres, she built a studio in the garden in 
which to pursue her vocation. 

Metchnikoff on several occasions came to England 


to take part in " congresses " or to give special 
addresses, and often stayed a day or two with me in 
London. 1 I was with him at the Darwin Celebration 
at Cambridge in 1909, and the last occasion when he 
came was to give the Priestley Lecture of the National 
Health Society in November 1912. At my request 
he selected " The Warfare against Tuberculosis " as 
his subject, and gave a most valuable account of the 
history and actual condition of that enterprise, 
relating the important results of his expedition to the 
Kalmuk Tartars for the purpose of studying the 
immunity from and the liability to infection by 
tuberculosis among that nomad population. The 
lecture was delivered in French, and I made a trans- 
lation of it which appeared with numerous illustra- 
tions in the journal called Bedrock, published by 
Constable & Co. I mention that publication here 
as it is the only one excepting the three lectures on 
" The New Hygiene " (Heinemann, London, 1906) 
originally published in an English form by Metchnikoff , 
and deserves more attention from the English medical 
public than it has received. 

I found Metchnikoff a delightful companion. He 
always had something new or of special interest to 
show to me at the laboratory some microscopical 
preparation, the digestive process in Protozoa, the 
microbian parasite of a water-flea, a new method of 

1 He received an honorary degree at Cambridge in 1891, and also 
attended the International Medical Congress in London in that year. In 
1901 he gave a lecture at Manchester on the intestinal flora. In 1906 he 
gave a course of three lectures in London on "The New Hygiene." I 
translated them for him, and they were published as a little volume by 



dark ground illumination with high powers (Com- 
mandant's method for film production), the newly 
discovered Treponema of syphilis, or the experimental 
inoculation of a disease under study. Sometimes I 
would lunch at his house, when, although he neither 
smoked nor took alcoholic drinks himself, he made a 
point of giving me first-rate claret and a good cigar. 
It was about the year 1900 that he arranged for the 
preparation of a pure " sour milk " made by the use 
of a special lactic ferment (selected and cultivated 
by hknself), and this he took regularly. I found it a 
most agreeable food, and for several years made it 
an article of my own diet. He was very careful about 
the possible contamination of uncooked food by 
bacteria and the eggs of parasitic worms, and in 
consequence had " rolls " sent to him from the bakers 
each in its separate paper bag, whilst he would never 
eat uncooked salads or fruit which could not be 
rendered safe by " peeling." This was not an excess 
of caution, but resulted from his characteristic deter- 
mination to carry out in practice the directions given 
by definite scientific knowledge, and to make the 
attempt to lead so far as possible a life free from 
disease. Often when I arrived in Paris he would 
invite me to lunch at one of the leading cafes, and 
though he ate very simple food himself took keen 
pleasure in ordering the best for me and thoroughly 
enjoyed the change of scene and the amenities of a 
first-rate restaurant. During one of his visits to 
London, I remember that he was invited, and I with 
him, on two or three occasions, by leading London 


physicians to dinner-parties. He was greatly shocked 
at the amount of strong wine which his hosts and 
fellow-guests consumed, and assured me that in Paris 
it would be injurious to the reputation of a physician 
were he not to set an example of either abstinence or 
great moderation. 

Metchnikofi was not only exceedingly gentle and 
courteous in his treatment of servants and employes, 
but he and his wife contrived on a very small income 
to help in a most substantial way poor neighbours 
and those who had met with misfortune whether they 
were of French or Russian nationality. They had 
many friends in the world of science and art, real 
workers and thinkers, including those who had not 
and those who had " arrived." With them I met 
and spent a long and interesting day with Rodin the 
sculptor and the son of Leon Tolstoi, who was 
working in a Paris studio. Among the pleasures 
which I have derived from the Life are the accounts 
of places such as Naples and Messina, where I 
stayed in order to study the embryology of marine 
animals as Metchnikoff did ; and also the appear- 
ance in these pages from time to time of old friends 
such as Nikolas Kleinenberg, whom Metchnikofi met 
at Messina in 1883. I had formed an intimate 
acquaintance with Kleinenberg at Jena in 1871, 
when he was working at his classical monograph 
on Hydra, and continued it at Naples in 1875. 
From Messina, where he became Professor in 1875, 
Kleinenberg sent me for publication in the Quarterly 
Journal of Microscopical Science his valuable memoir 


on the embryology of a species of Earthworm, and 
also rare and interesting specimens of Cephalopoda. 

Another great and noteworthy figure about whom 
all zoologists are glad to learn as much as possible is 
Kovalevsky. Metchnikoff made his acquaintance 
at Naples in 1864, and they formed a close friendship 
for one another. Later, in 1867, they shared the Baer 
Prize of the Petersburg Academy for their discoveries 
in embryology (p. 58). In 1868 Metchnikoff had a 
dispute with Kovalevsky as to the origin of the 
nervous system of Ascidia (p. 62), concerning which 
he subsequently admitted that he was wrong and 
Kovalevsky right. There is no doubt that Kovalevsky, 
by his numerous important investigations of inverte- 
brate embryology, and especially of that of Ascidia 
and Amphioxus, laid the foundation of cellular 
Embryology, and the modern study of the embryology 
of Invertebrates. Metchnikoffs contributions were 
also of great value and importance (pp. 51, 52, 53, 
and pp. 72 and 73), though he has not so great a 
triumph in animal morphology to his credit as 
Kovalevsky's discovery of the close identities of the 
development of organs in Ascidia and Amphioxus. 
I had long cherished profound esteem for Kovalevsky 
when in 1896 I met him and his daughter at Wimereux 
with Professor Giard. He came in the autumn of 
that year to London, but left unexpectedly owing to 
some nervous fear of annoyance by the police. The 
great position of Kovalevsky was deliberately ignored 
in a German history of Zoology, 1 published just before 

1 By Prof. Hertwig of Munich. 


the Great War. Metchnikoff describes Kovalevsky 
as a young man, small and timid, with shy but cordial 
manners and the clear sweet eyes of a child : he had 
(like Metchnikoff) for Science an absolute cult " no 
sacrifice was too great, no difficulty too repellent for 
his ardour." 

It is, I think, desirable to assure the reader of 
this book that the actual state of knowledge in 
regard to various subjects discussed in the Life at the 
time when they were made the subjects of study by 
Metchnikoff is fairly and correctly sketched, and the 
growth and development of his views and original 
discoveries are correctly given. But it must be 
remembered that this Life is not a critical discussion 
of the steps by which our knowledge of cell-layers, 
of intracellular digestion, and other factors con- 
tributory to Metchnikoff 's doctrine of Phagocytosis 
and its outcomes were reached. Others played an 
important if a subsidiary part in building up that 
knowledge. What we have here is an account of 
the growth of Metchnikoff's own observations and 
theoretical inferences, which were so independent, and 
founded on such decisive original observations, as to 
make him a solitary figure contending, and successfully 
contending, during the best years of his lifetime for 
the recognition of a great generalisation for long 
opposed by most of the medical and physiological 
authorities of the time, and finally established by his 
lifelong researches and those of his faithful pupils 
and coadjutors. The recognition of the validity of 


the doctrine of 'phagocytosis in relation to wounds, 
disease, immunity, and normal healthy life is the 
triumphant result of the scientific insight and bound- 
less energy of Elie Metchnikoff. 







1845. Panassovka MetchnikofFs parents Country life in 

Little Russia 1 


MetchnikofFs brothers and sister Childish characteristics 



1850. Journey to Slaviansk The coach attacked by peasants 12 


1851. Departure for Kharkoff Town life . . .16 


1853-1856. Leo MetchnikofFs illness Private tutors 

Botanical studies A memorable birthday . .19 


Ancestors of the Metchnikoff family The great "Spatar" Leo 

Nevahovitch 23 



1856-1861. The Kharkoff Lyce"e Bogomoloff and Socialism 
Atheism Natural History studies Private lodgings 
Private lessons in histology from Professor Tschelkoff A 
borrowed microscope First article Italian opera The 
gold medal ... .28 


An early love A schoolfellow's sister A pretty sister-in-law . 35 


1862. Journey to Germany Leipzig, Wiirzburg A hasty return 37 


1863. Kharkoff University Physiology The Vorticella 
Controversy with Kiihne The Origin of Species Gastero- 
tricha University degree . , . . .40 


1864-1866. Heligoland Giessen Congress Leuckart Visit 
to Leo Metchnikoff at Geneva Socialist gatherings 
Metchnikoffs discovery appropriated by Leuckart Naples 
Kovalevsky Comparative embryology Embryonic 
layers Bakounine and Setch6noff Cholera at Naples 
Gottingen Anatomical studies Munich ; von Sieboldt 
Music Return to Naples Intracellular digestion . 43 


1867-1868. Petersburg Baer Prize Return home Friend- 
ship with Cienkovsky Odessa Naturalists' Congress at 
Petersburg Departure from Odessa Zoological Lecturer's 
Chair at Petersburg Messina Enforced rest Reggio 
Naples Controversy with Kovalevsky Visit to the 
B. family Mile. F&Iorovitch Educational questions 
Difficulties of life in Petersburg . . . ,58 




1868-1873. Slight illness Engagement to Mile. Fddorovitch 
Marriage Illness of the bride Pecuniary difficulties 
Spezzia Montreux Work in Petersburg University 
The Riviera Coelomata and Accelomata St Vaast 
Panassovka Madeira Mertens Teneriffe Return to 
Odessa Bad news, hurried journey to Madeira Death of 
hiswife(1872) Return through Spain Attempted suicide 
Ephemeridse . . . . . .65 


1874. Anthropological expedition to the Kalmuk steppes 
Affection of the eyes Second expedition to the steppes 

The eggs of the Geophilus . . . .82 


1875. Studies on childhood The family in the upper flat 
Lessons in zoology Second marriage Private life Visit 

and death of Lvovna Nevahovna Conjugal affection . 86 


1875-1880. Metchnikoff at the age of 30 Lecturing in Odessa 
University, from 1873 to 1882 Internal difficulties 
Assassination of the Tsar, Alexander II. Further troubles 
in the University Resignation Bad health: cardiac 
symptoms Relapsing fever Choroiditis Studies on 
Ephemeridae Further studies on intracellular digestion 
The Parenchymella Holidays in the country Experi- 
ments on agricultural pests . . . .96 


1881-1882. Death of his father- and mother-in-law Manage- 
ment of country estates Agitation and difficulties De- 
parture for Messina with young brothers- and sisters-in-law 112 



1883. Messina Inception of the phagocyte theory Encourage- 
ment from Virchow and Kleinenberg First paper on phago- 
cytosis at a Congress at Odessa in 1883 The question of 
immunity Article in Virchow's Archiv, 1884 . . 115 


1884-1885. Ill-health of his wife and sister-in-law Journey 
to Tangiers through Spain Villefranche Baumgarten 
criticises the phagocyte theory . . . .123 


1886. A Bacteriological Institute in Odessa Unsatisfactory 
conditions Experiments on erysipelas and on relapsing 
fever .... ... 127 


1887. Hygiene Congress in Vienna Wiesbaden Munich 
Paris and Pasteur Berlin and Koch Failure of anthrax 
vaccination of sheep Decision to leave Kussia . .131 


1888. The Pasteur Institute Dreams realised Metchnikoff 
at 50 Growing optimism Attenuated sensitiveness 

The Sevres villa (1898) Daily routine . . .135 


1892. Opposition to the phagocyte theory Scientific con- 
troversies Experiments in support of the phagocyte theory 
Behring and antitoxins The London Congress 
Inflammation . . . . . .147 


Cholera Experiments on himself and others Illness of M. 

Jupille Death of an epileptic subject Insufficient results 154 




1894. Pfeiffer's experiments The Buda-Pest Congress 
Extracellular destruction of microbes Reaction of the 
organism against toxins Dr. Besredka's researches 
Macrophages The Moscow Congress Bordet's experiments 168 


1900. Immunity Natural immunity Artificial immunity . 168 


1893-1905. Private sorrows Death of Pasteur Ill-health 
Senile atrophies Premature death Orthobiosis 
Syphilis (1905) Acquisition of anthropoid apes (1903) . 181 


Researches on the intestinal flora Sour milk. . .196 


1908. The Nobel Prize Journey to Sweden and Russia A 

day with Leon Tolstoi . . . . .199 


Intestinal flora Infantile cholera Typhoid fever Articles on 

popular Science ..... 206 


1911. Expedition to the Kalmuk steppes to study tuberculosis 

Plague . . . . . . .210 


Further researches on the intestinal flora Forty Years' Search 

for a Rational Conception of Life . . .220 




Unpleasant incidents The fabrication of lacto-bacilli St. 
Le"ger-en-Yvelines Return to Paris First cardiac attack 
Evolution of the death instinct Notes on his symptoms 225 


1914. Return to St. Le"ger-en- Yvelines Norka Studies on the 
death of the silk-worm moth War declared Mobilisation 237 


1915. Return to Paris The deserted Institute Memoir on the 
Founders of Modern Medicine MetchnikofPs Jubilee 

Last holidays at Norka . . ,. " . ' . 244 


1916. Bronchial cold Aggravated cardiac symptoms Farewell 
to Sevres Return to the Institute Protracted sufferings 
Intellectual preoccupations Observations on his own 
condition The end Cremation . . .254 

EPILOGUE. .. . ' . . . . 276 


INDEX , 291 



ON a calm summer evening we were seated together 
on our terrace. 

On the preceding day, one who hardly knew my 
husband had come to ask him for information con- 
cerning his life, with the object of writing his biography. 
We were saying to each other how inevitably super- 
ficial and incomplete such a biography was bound to 
be ; how difficult such a task is for a biographer, even 
when fully informed ; how necessary it is to be 
thoroughly acquainted with a man and with every 
phase of his existence in order to give a truthful 
picture of his character and of his life. The intimate 
side is bound to remain more or less closed to a 
stranger ; in order to decipher it, it is indispensable 
for the writer of a biography to have lived in complete 
communion of spirit with its subject. Our long past, 
spent together, fulfilled all these conditions. 

My husband's whole life was well known to me. 
My mother-in-law had often told me vivid stories of 
his childhood ; he himself willingly talked to me 
about his past. As to the second part of his existence, 
we had lived it together. 

In order clearly to understand his character, at 


once both complex and one-sided, it was necessary to 
possess the key to his psychology. In his life, as in 
his work, everything was so closely knitted that it 
was impossible to understand the whole without know- 
ledge of every link of his evolution. 

In the soothing calm of that summer evening, I 
submitted my reflections to him ; he warmly en- 
couraged me, and I then and there resolved to write 
his biography. He advised me to relate his whole 
life without any reticence, considering that thus 
alone does a biography justify its existence. That 
advice was to guide me, within limits, for to dissect 
an individual life without touching other li ves as well 
is not always possible. 

Numerous were the difficulties before me ; yet, I 
considered the task as a mission, hoping, in spite of 
all, that this biography would present a true picture 
of the life and evolution of Elie Metchnikoff. 

We talked over this project for a long time. The 
moon now appeared above the trees, the soft light 
tracing silver designs through the ivy leaves. The 
lawn, the walnut tree in front of the house, and every- 
thing around us was bathed in peaceful radiance. 
Under its mysterious charm, we ceased to speak, we 
listened to the inward voices of nature and of our 
own hearts. 

In youth, vague reveries fill our minds ; after a long 
life, distant memories. ... He whose life I describe 
is no more. . . . Without his help my task could not 
have been accomplished. 

Often, when he was not too tired, he would sit 


comfortably in his armchair and recount to me with 
his usual spirit and animation some period or episode 
of his past. I read to him a sketch of the first part of 
this biography and a few chapters only of the second, 
which was hardly begun. Thus we spent many 
evenings, never to be forgotten. 

He wanted this biography written, for he held that 
the evolution of a mind, of a character, of a human 
life is always an interesting psychological document. 

During his long and painful illness, he urged me to 
relate the " last chapter " of his life ; he hoped that 
his attitude in the face of death might diminish the 
fear of it in others. Also he considered that men are 
rare who are conscious until the end ; even rarer, those 
who reach the development of the " death-instinct." 
Therefore, according to him, an example would be 

I have tried to accomplish his desire within the 
measure of my strength. 

The only object of this simple and truthful story 
is to show Elie Metchnikoff as he was, a help, a support, 
and a lesson to others. 

I dedicate this book to his dear memory. 


SfevBES, 15th Dec. 1918. 


Panassovka Metchnikoff's parents Country life in Little Russia. 

IN Little Russia, in the steppe region of the province 
of Kharkoff, is situated the land of Panassovka, which 
belonged to the Metchnikoff family. It is now sold, 
it has passed into strange hands, but it was once the 
patrimony of Ilia Ivanovitch, father of Elie Metch- 

The country around Panassovka is neither beautiful 
nor rich : steppes, hillocks covered with low grasses 
and wild wormwood ; a poor village, meagre vegeta- 
tion, no river ; the whole impression is a melancholy 
one. But what boundless space ! What soft, silver 
grey colouring ! And, in the mornings and evenings, 
what fresh, cool air, and what a delicious aroma of 
wormwood leaves ! 

The house of Panassovka, a little way from the 
village, is situated on a hill which slopes gently 
towards a pond. It is like that of any other middle- 
class landowner in Little Russia. It has only one 
storey and two nights of steps on the principal fa9ade, 
opening into a deserted courtyard with no view but 
the high road. On the other side a semicircular 
terrace, with columns and steps, leads to the garden, 
composed of a few meagre flower-beds and fruit trees, 
reaching to the pond. On the bank, a distillery and 
a very well-kept kitchen garden. 


The house is arranged inside in a commonplace 
manner, with no claim to beauty or comfort. The 
furniture, devoid of style or elegance, neither com- 
fortable nor fashionable, is distributed quite inartistic- 
ally. On the other hand, great care is evident in 
everything that pertains to the table : the cellars 
and larders are full of provisions, and obviously con- 
stitute the principal preoccupation of the masters of 
the house. And indeed the hospitable table of Panas- 
sovka is renowned throughout the neighbourhood. 

According to a very fine portrait, painted in 1835, 
Ilia Ivanovitch was at that time a handsome young 
man with regular features, tender blue eyes, and curly 
fair hair. He was very intelligent, but his mind had 
that sceptical turn which prevents men from taking life 
seriously and which paralyses activity. Moreover, he 
had an Epicurean temperament and was in the army. 

He had married, when very young, Emilia Lvovna 
Nevahovna, sister of one of his brother officers in 
the Imperial Guard, a very attractive and unusually 
intelligent girl. Her beauty was of the Jewish type, 
with splendid dark eyes, and she had a bright and 
lively disposition as well as a kind and tender heart. 
Her friends called her " Milotchka," which, in Russian, 
means " charming " ; in her old age she loved to 
relate that the great Russian poet, Pushkin, once said 
to her at a ball, " How well your name suits you, 
Mademoiselle ! " 

After his marriage, Ilia Ivanovitch remained in 
Petersburg, leading a merry life with his brothers-in- 
law, and giving no thought to the future ; it took 
him but a few years at that rate to spend the whole 
of his wife's inheritance. And three children were 
growing up whose future had to be thought of. It was 


then that Ilia Ivanovitch's distant estate was remem- 
bered, away in a remote part of Little Eussia. What 
energy, what perseverance had to be displayed by 
his wife before she could persuade him to take refuge 
there ! and how hard it must have seemed to the gay 
officer to leave the capital for the lonely and mono- 
tonous life of the country ! However, departure 
was decided upon. The two boys, Ivan and Leo, 
were placed in a school at Petersburg, to be prepared 
for the Lycee and the Law School. Ilia Ivanovitch 
obtained a post as Remount Officer for two Guards 
regiments, and started with his wife, his daughter, 
an aunt, and a younger brother, to settle down in the 

The family settled at first in the old Ivanovka 
house, where a son, Nicholas, was born. Though they 
wished to have no more children, one more child was 
born two years later, on the 16th May 1845 Elie 

The Ivanovka house was old and inconvenient ; 
Ilia Ivanovitch decided to build a new one at the other 
end of his estate, in a place called Panassovka, which 
thus became the family home. 

Emilia Lvovna threw herself into her domestic 
occupations with her usual energy and ardour. She 
was anxious to improve the situation, which had 
become precarious, and wished at the same time to 
create for her husband an environment suited to his 
Epicurean tastes. Ilia Ivanovitch loved cards and 
the table, both tastes easy to satisfy in the country, 
and which became the pivot of life at Panassovka. 
The great daily problem was the question of meals, 
and long conversations had to take place with the 
cook and with the housekeeper concerning catering. 


Thanks to serfdom, servants were very numerous 
and everything could be manufactured at home. 
The " dievitshia " (maid-servants' room) was crowded 
with maids, seamstresses, needle-women, washer- 
women, etc., under the direction of a fat, middle-aged 
woman named Duniasha. She wore a silk kerchief 
on her head, and was invariably clothed in a white 
dressing jacket and a brown skirt with white spots. 
A regular autocrat, she ruled her little world with a 
rod of iron ; as soon as her heavy, felt-slippered steps 
were heard, the maids whispered to each other, 
" Avdotia Maximo vna ! " conversations ceased, and 
every one became absorbed in her work. 

Among the male retainers, the first place was held 
by Petrushka, the valet. Careless and often drunk, 
he was nevertheless a good fellow ; he was usually 
to be found asleep behind the screen in the hall. The 
upper servants, the cook, coachman, and others left 
their work to be done by their underlings, the scullery 
boy, postilion, page-boy, etc. In fact, everything 
followed the routine usual in every Russian household 
in the time of serfdom. 

Emilia Lvovna directed the children's education ; 
her personal teaching consisted chiefly in tender 
indulgence, but it was she who chose the nurses and 
teachers. As long as the boys were small, their 
great-aunt Elena Samoilovna looked after them ; 
afterwards they were handed over to tutors and 
professors. Ilia Ivanovitch's activities consisted in 
buying horses at fairs and in studs and in convoying 
them to Petersburg. These journeys took a long time, 
by stages and relays of horses. Ilia Ivanovitch took 
advantage of them to gamble heavily and to enjoy 
pleasures which the country did not offer. 


Agriculture was very restricted at Panassovka, 
for the property consisted mostly of pasture land for 
horses and sheep. The younger brother, Dmitri 
Ivanovitch, had undertaken the management of the 
estate. He was entirely devoted to the family of his 
elder brother, whom he had followed into the country. 
Though only a few years younger, he used the respect- 
ful second person plural in speaking to Ilia Ivano- 
vitch, whilst the latter said " thou " to him. Dmitri 
Ivanovitch was tall, thin, and taciturn, a silent pipe- 
smoker. The lively Emilia Lvovna often said to 
him, " But why do you never talk, Mitienka ? " To 
which he invariably answered, "It is not every one 
who is as talkative as you are, Emilia Lvovna." Yet 
they were on the best of terms. Dmitri Ivanovitch 
would have gone through fire for his sister-in-law, 
as she well knew. She had the utmost confidence in 
him, and depended upon his support in every difficult 

At Panassovka the men spent the greater part 
of the day, and often even of the night, in playing 
cards ; games were organised between neighbours and 
relations, and that occupation was considered most 
important. Meals were prolonged indefinitely ; every- 
thing was served in abundance and eaten with a con- 
noisseur's appreciation, each dish being discussed. 
After the meal was over, the cook would make his 
daily appearance, and the next day's menu was drawn 
up by the whole party. After a siesta, gambling was 
resumed. Thus the days went by in the cult of good 
cheer and of cards, interspersed with conversations 
about horses and sometimes about politics. 

By this time Hia Ivanovitch was beginning to 
become bald and obese. It is difficult to define what 


was his inner life ; not even to his wife did he ever 
speak of it. As to his children, he petted them when 
they were small, but as they grew up, their intercourse 
with him was limited to kissing his hand morning and 
evening. He was not indifferent to their welfare, 
but left it entirely to his wife's active solicitude. 
The children were on very different terms with their 
mother ; not only did she spoil them, but also always 
eagerly shared all their childish interests. Owing to 
that, and to her bright and affectionate disposition, 
they looked upon her as their intimate friend and 

Masters and servants were on good terms, rela- 
tions between them were even remarkably human, 
according to the ideas of the time, and in spite of 
certain customs inherent to serfdom. For instance, 
the younger maids were punished by having their 
faces slapped and their hair pulled. Even the kindly 
and peaceable Dmitri Ivanovitch would soundly box 
his valet's ears when he found him drunk. At that 
time such things were not thought cruel or humiliating, 
but looked upon as a paternal correction. The 
peasants had confidence in their " barin " (master) 
and consulted him or appealed to his generosity when 
in trouble. 

Ilia Ivanovitch never opposed the free choice of 
his serfs in matrimony, a rare tolerance at that time. 
According to custom every betrothed couple came to 
salute him, the young man in his Sunday clothes and 
a fine, bright-coloured scarf, the girl wearing an em- 
broidered bodice and a head-dress of many-coloured 
ribbons. They knelt before him and bowed three 
times to the ground, then offered him sacramental 
loaves, hard and shaped like pine cones, on beautifully 


worked diapers. Ilia Ivanovitch and Emilia Lvovna 
blessed the bride and bridegroom with " ikons," 
embraced them, and gave them a sum of money for 
the wedding. 

The Metchnikofls were liked by their peasants 
and looked upon as good masters. 


Metchnikoff's brothers and sister Childish characteristics. 

THE two elder children, Ivan and Leo, were educated 
at Petersburg, whilst Katia, the only daughter, was 
brought up at home. Like all other girls of noble 
family, she was educated with the object of being 
suitably married. She was a slender, pretty brunette, 
like her mother, but less beautiful. Though sensitive 
and intelligent, she interested herself in nothing but 
the reading of French novels. There was a great 
difference in age between Katia and her little brothers, 
whilst there were only two years between them. 
Kolia (Nicholas) was the old aunt's favourite, a fine, 
handsome boy with velvety black eyes ; his slow and 
grave movements had earned for him the nickname of 
" Peaceful Papa." 

The youngest of the family, Ilia (Elie), on the 
contrary, was full of life and spirits. Fair and slender, 
with silky hair and a diaphanous, pink and white 
complexion, he had small, grey-blue eyes, full of 
kindliness and sparkle. ' Very highly strung and im- 
pressionable, his temper was easily roused, and he was 
so restless that he went by the name of " quicksilver." 
He always wished to see everything, to know every- 
thing, and found his way everywhere. When, after a 
long silence, there was a sudden outburst of many 
voices around the card-tables, he would rush to the 


drawing-room, saying, " Are they going to fight ? " 
He ran about the house all day, following his mother 
as she attended to her various duties ; he examined 
the provisions, tasted everything, and even went to 
the " dievitshia " to see what the maids were doing. 
He tried to sew or to embroider, exasperated every- 
body, and ended by being turned out. He would then 
look for something else to do, go to see whether the 
table was laid, inquire about the menu, and ask the 
queerest questions. He could only be kept quiet 
when his curiosity was awakened by the observation 
of some natural object such as an insect or a butterfly 
that he was trying to catch, or by watching the 
" grown-ups " at their card games. But, of all things, 
music fascinated him most, and he would remain for 
hours sitting by the piano listening without a move- 
ment. He was very much spoilt by his mother, who 
had a weakness for her Benjamin, and who also wished 
to make up for the very obvious preference shown for 
Kolia by the great-aunt. 

Moreover, Ilia was a frail little boy and often 
suffered from his eyes ; the doctor advised that he 
should not be allowed to cry or to rub his eyes, and, 
in order to avoid this, he was permitted to have his 
own way in everything. He was much too intelligent 
not to understand the advantage that the situation 
offered and was quick to profit by it. In the face of 
the least semblance of refusal or reproach, he would 
begin to rub his eyes and announce in a whining tone 
that he was going to cry. He was therefore very much 
spoilt and very capricious ; his mother said he was 
" neurotic " ; his sister, who often had differences 
with him, called him a " little beast." In reality, Hia 
was very good-hearted, tender, and loving ; he was 


affectionate, especially with his mother, and could 
always be managed by an appeal to his feelings. But 
if he was sensitive to kindness, he was equally so to 
the least injustice. He could not forgive his great- 
aunt the predilection which she exhibited on every 
occasion for Kolia ; for instance, at table, she would 
choose tit-bits for him, and Ilia observed with bitter- 
ness that she always reserved the chicken's breast for 
her favourite. Every time a chicken was served, 
poor Ilia followed the dish round the table with 
anxious eyes, and she invariably placed the coveted 
morsel in his brother's plate. 

When the day was over, Ilia was put into his little 
bed and told to " say his prayers and go to sleep." 
But he did not obey at once : after a thousand merry 
tricks, his eyelids would begin to close in spite of him ; 
then he would make up his mind to kneel and say his 
prayers, folding his little hands : " Lord, keep and 
preserve father, mother, great But suddenly 

remembering the latter's injustice towards him, he 
would correct himself hastily, " No, not great-aunt, 
she is too unkind ! " and continue, " My sister, my 
brothers, everybody, and myself, little Ilia." Still he 
did not go to sleep immediately ; a nervous child, he 
was frightened of being alone ; now and then he 
would lift his heavy lids to see if the maid was still 
there. Sometimes the latter, thinking he had gone 
to sleep, would leave the room on tiptoe. Hia, 
seeing her no more, would start, raise his head and, 
stretching his thin neck, send an anxious look around 
the room, faintly lighted by a night-light. The vacil- 
lating flame threw trembling and dancing shadows. 
Seized with intense terror, he would hide his face in 
his pillow and scream with all his might. Avdotia 


Maximovna would then rush to soothe him and 
soundly rate the servant girl, " Are you not ashamed 
to leave a noble child all alone ? " Hia would then 
go on sobbing for a little while, but, reassured after all, 
would presently sink into deep, childish sleep. 


Journey to Slaviansk The coach attacked by peasants. 

IN 1850 the children were taken to the baths of 
Slaviansk. On a warm summer day the heavy 
" berlin " coach, drawn by six horses with a postilion, 
rolled along the high road, across the steppes, followed 
at a distance by a " tarantass." l 

In the spacious, antique coach, with its dusty 
hood, sat Emilia Lvovna, with her three children ; 
the valet, Petrushka, dozed on the box, next to the 
coachman. The tarantass was occupied by Dmitri 
Ivanovitch and a cousin. 

The heat was oppressive. At the start every one 
was excited ; Emilia Lvovna was trying to remember 
if anything had been forgotten and was discussing 
with Katia the details of their installation at Slaviansk. 
The boys hung out of the windows, gazing at the 
horses, at the tarantass, and making all sorts of 
comments. Ilia was so restless and talkative that 
he was constantly being told, " Do be quiet ! Keep 
still ! " 

By degrees, however, children and " grown-ups " 
began to feel drowsy, owing to the monotony of the 
road, the heat, and the swinging of the carriage. The 
tarantass had disappeared, for Dmitri Ivanovitch 
wished to visit an aunt whose house was not far from 

1 Ungainly open carriage on high wheels and without springs. 


the road. The outline of a forest was now seen on 
the horizon ; it came nearer and nearer, and soon the 
coach stopped before the forest inn. Everybody woke 
up, the children were delighted to be able to run about 
and stretch their limbs. They begged their mother 
to let them go into the forest whilst the horses were 
resting, and obtained permission to go, but not too 
far, and with Petrushka. 

They ate an appetising lunch at the inn and the 
children ran off at a gallop. Everything delighted 
them, the underwood, grass patches, ravines, and 
mysterious paths. But they had hardly entered the 
forest when they heard a sinister, confused rumour 
in the distance ; they stopped to listen, and recog- 
nised the voices of a tumultuous crowd. The chil- 
dren's joyous excitement fell ; frightened and docile, 
they hastened to return to the inn, from which Emilia 
Lvovna, looking anxiously out of a window, was 
making urgent signs to them to return. The coach 
was still standing without horses, and, a little farther 
ofi, the latter were surrounded by a crowd of peasants, 
of whom many were completely drunk. They shouted 
vociferously, and closely pressed the coachman and 
the postilion, threatening to confiscate the horses and 
detain the travellers if they were not given a ransom 
of a thousand roubles. 

Terrified, the children clung to their distracted 
mother ; Ilia felt her trembling, and his own little heart 
fluttered like a bird that has been caught. The 
drunken peasants appeared to him like monstrous 
ogres or brigands about to capture, perhaps kill, his 
family and himself ; he could hardly keep back his 
tears. Already the peasants had bound the coach- 
man and the postilion and were taking away the 


horses. Clinging close to each other, the mother and 
children listened anxiously ; they thought again and 
again that they could hear the bells of the tarantass. 
At last it appeared in the distance, and the children 
joyously whispered, " There they are ! " They 
hastened to inform Dmitri Ivanovitch of what had 
happened. He at once went with his cousin towards 
the crowd, and negotiations were opened, but for a 
long time without result. 

At last the cousin had a happy idea ; he declared 
he would go back to his aunt's house in the neigh- 
bourhood and borrow the thousand roubles from her. 
The peasants consented to let him go alone, keeping 
the other travellers as hostages. After a time, which 
to the children seemed endless, the sound of the 
tarantass bells was again heard, accompanied this 
time by numerous heavy footsteps, and the vehicle 
reappeared, escorted by a company of soldiers com- 
manded by two officers. Instead of going to his 
aunt's, the cousin had gone to a neighbouring military 
camp and was bringing assistance. 

There was a sudden change of scene. Emilia 
Lvovna and Katia furtively made the sign of the 
cross. Ilia had let go of his mother's hand and was 
no longer clinging to her, but, stretching his head 
forward and opening his eyes wide, eagerly waited to 
see what was going to happen. " Now," he thought, 
" we shall not be captured ; it is their turn ; I am 
glad ! " And, perhaps for the first time in his life, 
his little heart was moved by feelings of hatred. 

In the meanwhile a repulsive scene was going on : 
a hand-to-hand struggle, invectives and screams. The 
peasants were securely bound. Men and women 
hastened from a neighbouring village ; one of the 


women slapped an officer's face. Furious, he ordered 
the soldiers to fill her mouth with earth ; she was 
thrown on the ground ; the new arrivals in their 
turn attacked the soldiers, and a regular battle raged. 

Ilia was alarmed, shaken, and profoundly disgusted 
with that exhibition of brutality. The coachman and 
postilion, their bonds unloosed, hastened to put the 
horses in, and whilst reprisals were still going on, the 
family hurried away. They reached Slaviansk with- 
out further trouble, excitedly talking over their adven- 
ture. This episode was the first deep and definite 
impression which remained on little Ilia's mind ; it 
struck him so much that he kept the memory of it 
during his whole life. 

From that moment he held crowds, violence, and 
all manifestations of brute force in the utmost horror, 
whatever their cause might be. 


Departure for Kharkoff Town life. 

THE following year was to be spent at Kharkoff. 
Katia was now seventeen and her marriage had to be 

The boys' life was still quite a childish one, made 
up chiefly of games and mischief. Kolia had been 
taught to read by the great-aunt ; Ilia had learnt by 
himself, asking people now and then for the name of 
some letter. He was able to read fluently quite early. 

The departure for KharkofE was a great event, 
prepared long beforehand. The children, delighted 
at the prospect of a change, impatiently waited for 
the moment to start. At last every one was seated 
in the coaches and, saying to the coachman, " Off ! 
God keep us," they started to drive along the high 
road through the steppes. 

Life at KharkofE was very much the same as 
at Panassovka, with social elements added. More- 
over, the children's liberty was somewhat restricted. 
Already on the journey they were given to understand 
that, in a town, they could not go out alone, nor 
shout in the streets, nor point at people and things 
with their finger, and that they should have to make 
less noise, even in the house. For the first time they 
unconsciously realised that their family was not the 
centre of the universe, that there were many others 



who also had to be taken into account. Ilia did not 
welcome this discovery. 

The flat occupied by the Metchnikoffe was on the 
first floor, above that of the owner of the house. 
One day when the children were running about, 
making a fearful noise, some one came up to say that 
the landlady was ill and begged that the noise should 
cease. Ilia, interrupted in the midst of a game, 
became furiously angry ; in his rage he seized a 
whistle, and stooping to a crack in the floor, whistled 
with all his might. It was only with much difficulty 
that he was induced to stop and to calm himself. 1 

The children's horizon soon widened ; Dmitri 
Ivanovitch took them to the theatre and a new 
and fantastic world opened out to them. The very 
next day they attempted a performance of the play 
they had seen ; soon, on Kolia's suggestion, they 
began to compose plays for themselves. Kolia wrote 
a drama entitled " Burning Tea," in which the hero 
having offered his friend tea that was too hot, the 
latter burnt his tongue ; a duel ensued, etc., etc. 
Ilia hastened to follow his brother's example. He 
composed something in the same style, but even more 
absurd. Having realised that it was so, he gave up 
literature. That period was for him a series of dis- 
appointments which perhaps helped to lead him to 
the path he was ultimately to follow. His brother, 
following the " grown-ups' " example, played cards 
with other boys or with the maids. Ilia attempted 
to do the same, but his nervousness left him no self- 
control ; he lost continually and games generally ended 
in quarrels and tears ; he became disgusted with 

1 Metchnikoff himself insisted upon the recital of this episode, for which 
he had felt some remorse. He considered that, in a biography, disagree- 
able traits were not to be omitted. 


cards for the rest of his life. Kolia was fond of 
muscular exercises, such as gymnastics, wrestling, etc. 
Ilia, younger and therefore weaker, was constantly 
humiliated, and his pride kept him away from physical 
amusements. Thus, by means of elimination, he 
became gradually isolated from surrounding influences. 
But, at that time, no new element had intervened in 
his daily life and he spent his existence in the gentle 
warmth of his mother's tenderness, absorbed in his 
childish games and studies. 


Leo Metchnikoff's illness Private tutors Botanical studies 
A memorable birthday. 

IN 1851, in the middle of the winter, the Metchni- 
koffs heard that Leo, their second son, was suffering 
from hip-disease, and the doctors advised that he should 
be taken away from Petersburg. Poor Emilia Lvovna 
was in great despair and shed many tears ; her 
brother-in-law, Dmitri Ivanovitch, calmly announced 
that he was going to fetch Leo. He took his great 
fur coat, his fur cap and fur-lined boots, and started 
that very day for Petersburg by coach. He took but 
the necessary time to go and to bring Leo back, only 
stopping at relays to change horses. 

The boy was then thirteen years old, handsome, 
gifted, and intelligent ; he walked with crutches, but 
his general health seemed good, and it was decided 
that he should work at home to prepare for the Lycee, 
under the tuition of students as tutors. Thus a new 
element was introduced into the family life. 

In 1853 Leo had as a tutor a student named 
Hodounof , a very intelligent young man, who wished 
not merely to teach him but to impart to him the 
love of science. Leo was extremely gifted and worked 
with great facility, but he lacked concentration and 
was therefore somewhat superficial. This cooled his 
tutor's enthusiasm, whilst on the other hand he 



became more and more interested in little Ilia. It 
was in the course of country walks that they were 
drawn together. Hodounof used to take Leo for 
walks in order to study the local flora, and Ilia came 
out with them, at first for the sake of the exercise. 
But soon he became interested in the flowers and 
showed so much taste for botany that he attracted 
Hodounof 's notice ; soon the tutor's interest became 
concentrated on the little boy and he gave him serious 

It was with a real enthusiasm that Ilia gathered 
and studied plants ; he soon became thoroughly 
acquainted with the local flora. He thought himself 
very learned already and wrote memoirs on botany. 
Passionately fond of teaching, he used to offer all his 
pocket-money to his brothers and other children to 
induce them to hear lectures which he gave them. 
His vocation was fixed from that moment. He was 
then eight years old. 

When the family returned to Kharkoff he spent 
all he had in buying books on natural history, which 
he read with passionate interest. These contained 
many things that he could not understand, but his 
curiosity was all the greater. When he was eleven 
years old his passion for natural history almost cost 
him his life. While fishing for hydra in a small pond 
he was so eager that he fell into the water and was 
only pulled out with great difficulty. 

That particular day, his own and his father's name 
day, was nearly fatal to him, not only through water 
but through fire. It was a family custom to hold a 
great gathering of friends and relations at Panassovka 
on St. Elias's day. Preparations for the feast began 
days beforehand ; the whole household was in a turmoil. 


On that particular St. Elias's day, so many guests 
came to Panassovka that there was not enough room 
in the house to accommodate them all, and the 
children were transferred to a pavilion outside the 

Whilst in the drawing-room people were talking 
and playing cards, the servants were holding rejoicings 
of their own. Towards night-time the majority of 
the coachmen and footmen brought by the guests 
were completely drunk ; a cigarette imprudently 
thrown on some hay started a fire. Soon the stables 
were ablaze and many horses perished in the flames, 
in spite of every effort to save them. Presently the 
wind changed in the direction of the pavilion and the 
thatched roof caught fire. There was a rush to save 
the children, who were with much difficulty taken out 
through a window. 

In spite of intense terror, Ilia's first thought was 
for his baby nephew, the son of his sister, who had 
then been married a year ; he ran in affright all over 
the house searching for the child, and only became 
calm again after he had ascertained that it had been 
carried out into the garden. 

Katia being married there was now no reason to 
spend the winter in the town. The father and mother 
therefore remained at Panassovka and Dmitri Ivano- 
vitch took the boys to Kharkoff , where they entered the 
Lycee. They had been well prepared by their tutors, 
and moreover spoke French and a little German, 
having had special teachers for these languages. 
Their French tutor, M. Garnier, was gay, boastful, 
and pretentious; his idea of teaching them French 
literature was to memorise Beranger's chansons. He 
was passionately fond of shooting and gave to that 


sport as much time as he could, greatly to the detri- 
ment of his pupils' studies, for they were not allowed 
to accompany him for fear of an accident. Their 
mother, perhaps on account of her weak heart, was 
so nervous that they were discouraged from any 
sporting tastes. The German tutor also neglected 
the children : his favourite occupation consisted in 
drinking beer. On one occasion he gave so much to 
little Ilia that the boy conceived a lifelong distaste 
for beer. Ilia took advantage of his tutors' indiffer- 
ence to devote himself to his favourite study of 
natural history. His vocation was so obvious that it 
could not be mistaken. It seems a strange thing 
that a passion for science should have developed in 
so inappropriate an environment. Evidently the 
first impulse was given by Hodounof, but, if his 
influence stimulated this passion, it cannot have 
created it. This vocation probably had a deeper 
source, and in order to discover it we should perhaps 
look back into the antecedents of the Metchnikoff 


Ancestors of the MetchnikoS family The Great Spatar Leo 

THE Metchnikoff family made no show of family 
pride ; one old aunt, however, was extremely proud 
of one of their ancestors, the Great "Spatar" (sword- 
bearer). The following is the account given of this 
ancestor by E. Picot, after a Moldavian chronicle. 1 

Few men led such an adventurous lif e or made themselves 
glorious through such varied gifts as did Nicholas Spatar 

His name is connected with the history of Moldavian, Greek, 
Russian, and Chinese literature. His origin, his talents, his 
crime, the mutilation he suffered, his audacious journey across 
the whole of Asia to reach Pekin, the valuable information 
which he gathered during his embassy at the Court of the 
" Son of Heaven," everything conspires to excite curiosity 
concerning him. 

Spatar was born in Moldavia in 1625. While yet 
very young he went to Constantinople, where he 
studied theology, philosophy, history ancient and 
modern, Greek, Latin, Slavonic and Turkish. He 
afterwards went to Italy to study natural science and 
mathematics. On his return to Moldavia he soon 
became known for his erudition, acquired great 

1 Chronicle of John Necidua. 


influence, and became much appreciated at Court. 
Owing to clever political intrigues he preserved the 
simultaneous favour of several enemy princes, one 
of whom, Stepanita, covered him with benefits and 
honours. Nevertheless, Spatar wrote to Constantine 
Bassarab, in Poland, advising him to come and to 
overthrow Stepanita 's throne. He sent his letter 
inside a hollow cane ; Constantine, however, did not 
wish to launch himself into such an adventure, and 
indignantly sent the hollow cane and the letter to 
Stepanita himself. At first the prince, naturally 
angry, thought of having Spatar executed ; he spared 
his life for the sake of his talents, but condemned him 
to have the tip of his nose cut off. Spatar went to 
Germany, where, says the naive chronicler, a doctor 
made his nose grow again. He came back to Mol- 
davia for a short time and then went to Russia. 
Thanks to his knowledge of languages, he was made 
an interpreter at the Court of the Tsar Alexis 
Michailovitch, and was the first tutor of his son 
Peter the Great, whom he taught to read and to 

In 1674 the Tsar Alexis Michailovitch entrusted 
Spatar with a mission in China, where he was to open 
negotiations with a view to commercial and political 
relations between Russia and China. In the course 
of his journey Spatar carefully collected all possible 
information concerning the countries he traversed. 
He thus gathered much interesting geographical 
knowledge and highly important data concerning the 
commercial value of Asiatic rivers, and specially the 
Amour river. 

At Pekin, Spatar rapidly learnt the Chinese lan- 
guage, occupied for three years the post of ambassador 


in China, and returned to Russia bringing back most 
valuable information and many rich presents given 
him by the Emperor of China. 

All this had excited the jealousy of the Muscovite 
courtiers ; they took advantage of the coincidence 
between the death of the Tsar and Spatar's return to 
deprive him of his treasures and to have him exiled 
to Siberia. But, when Peter the Great ascended the 
throne, Spatar succeeded in making a letter reach him 
relating his misfortunes, and the Tsar recalled him, 
gave him back his property, and showered honours 
upon him. Spatar again became interpreter of the 
Embassy ; Peter consulted him in all Far-Eastern 
questions, and gave him confidential documents to 
translate into foreign languages. 

Spatar's literary activity was vast and varied. 
He translated the Bible from the Greek into Rouman- 
ian ; he wrote a chronicle on the origin of Roumania, 
articles on theology, a Greco-Latin-Russian dictionary, 
and a work entitled Arithmetic, in which he discussed, 
by means of numbers and figures, questions of Theo- 
logy, Philosophy, and Ethics. He dealt in his writings 
with Art, Archaeology, and History; described his 
Siberian travels, China and the Amour river, and made 
numerous translations of diplomatic documents. His 
erudition was such that his contemporaries appealed 
to his knowledge as they would have consulted an 

He had married a Muscovite and had several sons 
and grandsons. Three of his nephews came from 
Moldavia to join him and entered the Russian army. 
He died in 1714 at the age of 80. Such is the history 
of the " Great Spatar." 

The following notice is to be found in Brockhaus 


and Effrone's Encyclopaedia : " The Metchnikoffs are 
a noble family, descended from a Moldavian Boyar, 
the Spatar (sword-bearer) Joury Stepanovitch, 1 who 
came to Russia with Prince Cant emir. Peter the 
Great gave this Boyar large land estates. His son 
took the name of Metchnikoff (Russian translation 
of Sword-bearer)." 

The following generations included military men 
chiefly, one sailor, one mining engineer, one senator, 
but no scientific men. 

On the mother's side, Elie Metchnikoff had no 
ancestor as remarkable or as romantic as the great 
Spatar. Yet his grandfather, Leo Nevahovitch, was 
a very intelligent and highly cultivated man. He had 
been Farmer-General for tobacco in Poland. A Jew 
by race, he took to heart the persecutions directed 
against his co-religionists and defended them in 
literary newspaper articles. Nevertheless he accepted 
indirect advice from Alexander I. and let himself be 
baptized. He adopted the Lutheran religion and his 
children were brought up in it. 

At the beginning of the Polish Revolution in 1830, 
Nevahovitch was warned that his house was about 
to be sacked ; the warning reached him as he was 
peacefully enjoying a theatrical performance. He 
hurried to prepare for departure and left Warsaw 
with his family for Petersburg, where he lived on his 
income. Having given up business, he took up literary 
work and translated German philosophical works, 
made friends in the literary world, and knew Pushkin 
and Kriloff. His children, Emilia Lvovna amongst 
others, inherited his intellectual gifts. One of his 
sons was a remarkable caricaturist and edited a cari- 

1 This Boyar was no doubt a nephew of the Great Spatar. 


cature newspaper which was very well known at the 
time. The Nevahovitch family produced no men of 
science. Metchnikofi himself considered that he had 
inherited his mother's disposition and turn of mind. 
In any case, his ancestors on both sides included 
talented individuals, from whom he may have 
inherited his gifts and his innate taste for science. 


The Kharkofi Lycee Bogomoloff and Socialism Atheism Natural 
History studies Private lodgings Private lessons in histology 
from Professor Tschelkoff A borrowed microscope First article 
Italian Opera The gold medal. 

IN 1856 Dmitri Ivanovitch took the boys to Kharkoff 
in order to make them enter the Lycee. They passed 
their entrance examination quite satisfactorily ; Kolia 
was admitted into the fifth class and Ilia into the one 
below it. They were day boarders and lived in the 
house of one of their former tutors. 

This was at a time when the new and liberal reign 
of Alexander II. was giving birth to many hopes ; 
the Lycees preserved but insignificant traces of the 
hard regime of Nicholas I. Previous narrow and 
doctrinal teaching was giving way to a current of 
realistic and rational ideas, physical and natural 
science had become the vogue, and professors were 
trying to come into touch with their pupils and to 
influence their intellectual development. The boys 
on their side were founding mutual instruction clubs, 
attending popular Sunday lectures, interesting them- 
selves in social questions in fact the revolutionary 
movement was beginning to strike root. Life in 
general was intense, aspirations exalted, and hopes 

During his first school year Elie worked assidu- 
ously in all branches of the curriculum, and his 


name soon appeared on the honours list. The 
Eussian language teacher became his friend, and 
greatly contributed to his development by choosing 
for him books of general knowledge. Under this 
direction Elie read, among other things, Buckle's 
History of Civilisation, which had at that time a very 
great influence on the young Russian mind. Accord- 
ing to the author's principal thesis, the progress of 
humanity depended chiefly upon that of positive 
science ; this idea sunk deeply into the boy's mind and 
confirmed his scientific aspirations. 

When he reached the fifth class he formed a 
friendship with one of his school-fellows, Bogomoloff, 
who had great influence over Elie's ulterior develop- 
ment ; he was the son of a colour manufacturer, and 
his elder brothers were studying chemistry at the 
Kharkofi University with a view to applying it to 
their industry. They had travelled abroad and had 
brought back novel ideas and books forbidden by the 
Russian censorship ; they influenced their young 
brother, who in his turn initiated Elie. It was thus 
that the latter became acquainted with materialistic 
ideas and social theories ; he read the Popular Star, 
the Bell of Herzin, and other publications prohibited in 
Russia. Little by little he lost the faith which he had 
held when under his mother's influence. Atheism, how- 
ever, was to him more interesting than disappointing ; 
it incited in him a state of general criticism. Ardently 
passionate in this as in all things, he preached atheism 
to others and received the nickname of " God is not." 
The course of teaching at the Lycee did not escape his 
criticism ; when he had reached the fourth class he 
omitted those exercises which seemed to him devoid 
of interest. On the other hand, he plunged with 


passion into the study of natural science, botany, 
and geology. 

He had ceased to be a model student, but his 
scientific aspirations became stronger from day to 

In order to cultivate foreign languages, the two 
brothers had been placed in a boarding-house where 
morals were strict and patriarchal, the food bad, and 
the director's sermons long and tedious. None of 
these things suited Elie. This regime, with the addi- 
tion of dancing lessons, inspired him with the deepest 
aversion ; he resolved to obtain from his parents per- 
mission to take furnished rooms for himself and his 

In spite of the current of political exaltation which 
was then universal in Russia, Elie was too deeply 
immersed in his studies to be carried away in that 
direction. He did at one time attend popular 
lectures and the political gatherings of the students, 
but he felt that science was his real vocation. He 
was so early and so completely absorbed by it that 
he was not interested in the great movement for 
the emancipation of the serfs. It is true that, at 
Panassovka, the question was not acute as elsewhere, 
the serfs being quite happy ; however, the fact remains 
that it was his passion for science which kept him, 
in spite of his exalted ideas and ardent soul, apart 
from the noble movement for liberation. 

In the third class he made friends with a group 
of students who were devoted to science and to intel- 
lectual culture. Elie, owing to his ardour and 
vivacity, played the part of a ferment in that little 
circle, each member of which was to make a special 
study of certain scientific branches in order that they 


might together edit a new encyclopaedia of human 
knowledge. He studied German so as to read in 
the original the classical materialistic writers, Vogt, 
Feuerbach, Buchner, Moleschott, etc. The Lycee 
lectures were relegated to the background. Never- 
theless, owing to his great facility of assimilation, 
he was successful in every branch. Plans for his 
ulterior activities were soon definitely fixed. 

At that time of intense intellectual effervescence 
in Russia, libraries were invaded by a number of 
translations of works on natural science. Elie absorbed- 
them with avidity, and read amongst others a Russian 
translation of Bronn's book on the Classes and Orders 
of the Animal Kingdom. He saw for the first time in 
the plates of that work pictures of micro-organisms, 
amoebae, Infusoria, Rhizopoda, etc. That world of 
lower beings impressed him so strongly that he resolved 
from that moment to devote himself to the study of 
them, that is, to the study of the primitive mani- 
festations of life in its simplest forms. 

He was then fifteen years old. The two brothers 
now obtained from their parents permission to live 
in furnished rooms, an independent arrangement 
which allowed each of them to satisfy his individual 
tastes. Apart from the Lycee, Kolia spent his time 
in playing cards and billiards and in other amuse- 
ments, whilst Elie worked with ardour, his only 
recreations being music and debates on abstract 
subjects. When he entered the second class he had 
become completely specialised. In order to tackle 
serious scientific studies, he tried to come into touch 
with one of the University professors. The University 
of Kharkoff was still making use of ancient methods ; 
teaching was given by means of manuals, with prac- 


tical application ; but Elie, who did not know that, 
dreamt of finding in laboratories assistance and means 
of, at least, undertaking personal scientific work. He 
attended a lecture on comparative anatomy, and, in 
order not to appear too young, he wore his ordinary 
clothes instead of the Lycee uniform. After the lecture 
was over, he shyly approached the professor and 
begged to be allowed to study protoplasm under his 
direction. The professor received him coldly, and 
told him in a pedantic tone that he was in too much 
of a hurry, and that he should first of all finish his 
course at the Lycee and then get admitted into the 

It was a disappointment for the eager boy ; how- 
ever, he did not lose heart but continued to attend 
divers University lectures, clinging to the hope that 
another professor might be more sympathetic. He 
was pleased with the lectures of a young physio- 
logist, Tschelkofi by name, and decided to make 
another attempt. This time he was successful. The 
professor received him kindly and consented to give 
him private lessons in histology. Then, fired with a 
passionate desire to produce something personal in 
medical science, and attracted by Virchow's cellular 
theory, he dreamt that he might create a general 
theory of his own in medicine. In order to increase 
his scientific knowledge, he undertook with his friend 
Zalensky the translation of Grove's work, The Unity 
of Physical Forces. The professor of chemistry and 
natural history willingly encouraged the two boys 
in this work, to which they gave up the whole of the 
school year. Elie wasted no opportunity of learning ; 
during those lectures which did not interest him he 
used to read scientific books. One day that he was 


doing so during catechism he did not notice that the 
priest, wishing to know what he was reading, had 
come up to him. The latter, however, was greatly im- 
pressed by the title of Radlkoffer's learned work on 
The Crystals of Proteic Substances ; he returned the 
book without a word and never interfered with him 

Through the assistance of some medical students, 
Elie obtained the loan of a microscope ; he studied 
Infusoria and imagined that he had made divers 
discoveries ; he hastened to write an article, and sent 
it to the only scientific Russian paper then in existence, 
the Bulletin of the Moscow Society of Naturalists. To 
his great joy his MS. was accepted, but before long 
the young scientist perceived that his deductions were 
erroneous, for he had mistaken phenomena of degener- 
escence for phenomena of development. He was able 
to stop the publication of this article, the first he ever 
wrote, and it never appeared. 

Thanks to Tschelkoff, who lent him a microscope 
for the duration of the holidays, he was able to study 
the local fauna of inferior animals. At the beginning 
of his last year at the Lycee, he read a text-book of 
geology by a Kharkofi professor and, with juvenile 
assurance, wrote a critical analysis of it. Inserted in 
the Journal de Moscou, this was Elie's first publica- 
tion ; he was then sixteen years old. Encouraged 
by this success, he sent several other criticisms, but 
they were not accepted. 

The last examinations were coming near : Elie 
wished to obtain the gold medal, not only out of pride, 
but in order to prove to his parents that he deserved 
their assistance in order to go abroad to continue his 
studies. He therefore provisionally suspended his 


favourite pursuits and resumed the study of the long- 
neglected school programme. The last examinations 
took place in the spring of 1862. It happened to be 
the Italian Opera season and Elie could not resist the 
temptations offered him by music. In order to make 
up the time, he often had to work the whole night 
long at the cost of severe fatigue. 

In spite of this complication, he passed his exam- 
inations brilliantly and obtained the gold medal. 
He now wished for nothing but to devote himself to 
scientific study. 


An early love A schoolfellow's sister A pretty sister-in-law. 

IN spite of his precocious vocation, Elie was in no 
wise indifferent to his surroundings. His mind was 
sensitive and impressionable and his affections deep 
and tender, especially where his mother was con- 
cerned. He never undertook anything without con- 
sulting her, a sweet habit which he preserved even in 
his maturity. 

It was already at the age of six that he received 
his first love impression : a lady came on a visit to 
Panassovka with her little girl of eight, a lovely curly- 
headed child, sweet and graceful, a living floweret. 
Ilia could not admire her enough, and was most lavish 
in his attentions, offering her flowers and fruit, in- 
venting games to amuse her and trying by every 
means to make himself agreeable to her. The presence 
of this charming little girl caused him great joy and 
tender emotion ; he wished that she might never go 
away. . . . But the visit soon ended, and this first 
idyll was short-lived ; new impressions were not long 
in replacing it. Nevertheless the picture of the 
pretty child was so deeply impressed in his mind that 
he never forgot her. 

The second time he fell in love was when he was 
already at the Lycee ; one of his schoolfellows had a 
very pretty sister whom Elie used to meet on half- 



holidays. He admired her from afar, and tried to 
contrive opportunities of meeting her ; she was the 
object of his dreams for the whole of one term. 

But he was presently to be seized by a more serious 
feeling. When he was in the third class at the Lycee 
he came as usual to Panassovka for the summer 
holidays and found there a new inmate, his elder 
brother's young wife. Soon, to his own astonish- 
ment, he found that the image of his last winter's 
passion was being effaced by that of his sister-in-law. 
She, a pretty, fashionable girl, was bored with country 
life ; she criticised the simple habits at Panassovka 
which formed a sharp contrast with her tastes ; she 
soon became very unpopular and, feeling lonely and 
bored, tried to attract her young brother-in-law. 
Elie, at first a willing comrade, soon found himself 
harbouring a more tender feeling for his sister-in-law ; 
she complained to him of the family's hostility, 
declared herself misunderstood, and easily excited 
the pity and sympathy of the sensitive boy. He 
became her ardent defender and went so far as to 
fight her battles, even with his mother, whom he 
reproached with fancied injustice. For nearly four 
years he remained under his sister-in-law's sentimental 
influence. He afterwards freed himself completely 
from it, but the fact remains that she was the first 
woman who inspired real sentiment in his youthful 


Journey to Germany Leipzig Wiirzburg A hasty return. 

DURING his later years at the Lycee, Elie had attended 
several courses at the Kharkofi University and had 
realised the inadequacy of the teaching and the im- 
possibility of any personal research work in the 
laboratories. His greatest desire, therefore, was to 
go abroad to study. At that time, the German 
universities, being nearer, chiefly attracted Russian 
students. Their laboratories were widely opened to 
foreigners, and lectures were being given by a pleiad 
of celebrated professors. 

In order to attain his object, Elie took care to 
secure his mother's support. It was not very dim- 
cult, for she believed in her son's scientific future and 
was anxious to help him ; she succeeded in convincing 
his father and, by means of serious sacrifices, the 
necessary sum was procured. Elie, who was espe- 
cially interested in the study of protoplasm, chose 
the University of Wurzburg, where the celebrated 
zoologist Kolliker was lecturing. Thinking that in 
Germany the term began in September, as in Russia, 
he hastened to depart. The journey at that time was 
long and complicated ; yet, in spite of much fatigue, 
Elie only stopped one day in Berlin and hurried to 
Leipzig, the centre of the book trade, in order to 
procure the necessary books. He reached Leipzig in 



the evening and was greatly embarrassed, not knowing 
where to find a lodging. A young German in the 
station offered him a room in his own family's house 
and took him there. The next morning, very early, 
Elie ran out to buy his books and, in his haste, forgot 
to note the number of the house and the name of 
the street ; it was with the utmost difficulty that he 
found the place again. Much disturbed by this mis- 
adventure, he hastened to start for Wiirzburg and, 
on arriving there, met with a great disappointment ; 
all the professors were absent, this being the middle 
of the holidays, and the lectures were not to begin for 
six weeks. The poor boy, thus alone for the first time 
among strangers, felt completely lost. He was given 
the address of some Eussian students and he hastily 
sought them out, full of joy and hope, only to be 
received coldly and distrustfully by his compatriots. 
After this discouraging reception, he sadly proceeded 
to look for a room, and having found one in the house 
of a disagreeable old couple, he brought his bag there. 
But, as he began to unpack it, he was seized with a 
feeling of such utter despair that he hastily put his 
luggage together again and announced to his elderly 
hosts that he was going. Surprised and indignant, they 
abused him so brutally that his distress only increased ; 
he rushed to the station, took the first train, and 
returned to Panassovka without a stop. This hurried 
return disconcerted his family, but, seeing the state 
he was in, nobody reproached him. His mother had 
felt much anxiety on his account, and was in fact not 
sorry to keep him a little longer under her wing. 
Thus, in dismal failure, ended that first journey 
abroad, so ardently desired. The result might have 
been very different if Elie had reached Wiirzburg at 


the right moment, or if the Russian students had been 
more friendly. Too young and too impressionable to 
bear absolute solitude, he could only have been saved 
by his favourite studies or by a friendly environment. 
His plans and fair dreams had been overthrown by a 
series of simple mishaps. 


Kharkoff University Physiology The Vorticella Controversy with 
Kiihne The Origin of Species The Gasterotricha University 

THERE was now no choice and he had to resign him- 
self to the Kharkoff University. There is not much to 
relate about this period, which was but a fugitive 
episode in the course of Elie Metchnikoff, for the 
" Alma Mater " did not have upon him either the 
influence or the prestige which it generally exerts upon 

Whilst the stream of new ideas had already reached 
the Lycee, the University of Kharkoff had remained 
extremely conservative ; this was owing to the fact 
that the Lycee professors were young men, whilst those 
of the University were elderly and old-fashioned. 
Officials rather than scientists, they were content with 
ancient methods, and lectured without practical work, 
from obsolete and ill-chosen manuals. A few of them 
drank, others neglected their work. In the Medical 
and Natural Science Faculties, only two agreges were 
newly appointed, Tschelkoff, the physiologist we have 
already mentioned, and a chemist named Beketoff. 
These two were indeed scientists and master-minds, 
and it was only under their direction that any one 
did any serious work ; the other lectures were pure 
formalities. Elie wished to go in for medical studies 



but his mother dissuaded him. " You are too sensi- 
tive," she said, " you could not bear the constant 
sight of human suffering." At the same time, 
Tschelkoff suggested the Natural Science Faculty as 
being more appropriate to purely scientific activity. 
Elie accepted his opinion and began to study physio- 
logy under his direction. His great desire was to 
embark at once on personal research, and his teacher 
advised him to study the mobile stalk of a ciliated 
Infusorian, the Vorticella. The question was to deter- 
mine whether this stalk presented any analogy with 
muscular tissue and whether it offered the same 
reactions. Elie set to work with ardour and found 
that the stalk of the Vorticella had no muscular 
character. His memoir on the subject appeared in 
1863 in Muller's Archives. It provoked a severe, even 
brutal, answer from the celebrated physiologist Kuhne 
which deeply grieved the young scientist and, stimu- 
lating his energy still further, incited him to repeat 
his experiments. He obtained the same results as 
the first time, and answered Kuhne in a somewhat 
bitter manner, the latter's tone having stirred his 

Meanwhile, Elie was yearning for independent and 
more general study. During his unsuccessful journey, 
he had acquired in Leipzig many recently published 
scientific books, and, among them, Darwin's Origin of 
Species. The theory of evolution deeply struck the 
boy's mind and his thoughts immediately turned in 
that direction. He said to himself that isolated forms 
which had found no place in definite animal or 
vegetable orders might perhaps serve as a bond be- 
tween those orders and elucidate their genetic rela- 
tionships. This leading idea made him choose for 


his researches some very singular fresh- water crea- 
tures, partly like Rotifera and partly like certain 
worms of the Nematode group. He succeeded in 
establishing a new intermediate order which he named 
" Gastrotricha," and which was straightway accepted. 

The whole of his first year at the University was 
given up to those special studies. As he was fully 
aware that the teaching of the University did not 
answer to his aspirations, he resolved to remain there 
as short a time as possible, and to get through the course 
of studies in two years instead of the four which were 
usual. In order to succeed in doing so, he provision- 
ally gave up his scientific researches, attended the 
lectures as a free auditor, and spent the whole of the 
second year in cramming for the " candidate " exam- 
ination, which answers to a Licentiate in Western 
universities. It happened again this time that the 
examinations coincided with the Opera season, but, 
though he indulged in his passion for music, he 
succeeded, by dint of a supreme effort, in passing them 
very brilliantly. 

Having gone through the University at such an 
accelerated pace, he did not come into contact with 
other students, who, themselves chiefly preoccupied 
with politics, took little interest in a youth so ex- 
clusively absorbed in science. He therefore formed 
none of those attractive juvenile friendships which 
he had enjoyed at the Lycee. His hasty University 
studies necessarily left lacunae in his general know- 
ledge, a fact which he afterwards keenly deplored. 

With the exception of Tschelkoff, his teachers 
had had no decisive influence on his career, and his 
two years at the University formed but a colourless 
episode in his life. 


Heligoland Giessen Congress Leuckart Visit to Leo Metchnikoff 
at Geneva Socialist gatherings Metchnikoff' s discovery appro- 
priated by Leuckart Naples Kovalevsky Comparative em- 
bryology Embryonic layers Bakounine and Setchenoff Cholera 
at Naples Gottingen Anatomical studies Munich ; von Sieboldt 
Music Return to Naples Intracellular digestion. 

ELIE still had his Licentiate thesis to prepare. In 
order to do so, he decided to spend two months in 
the island of Heligoland, of which the flora and fauna 
were very attractive to naturalists. In spite of his 
previous failure, his parents made no objection to his 
departure ; they gave him the little money they could 
spare and Elie started, in 1864. 

As soon as he arrived in Heligoland he became 
absorbed in his work. He proceeded with his idea of 
bringing light upon the genealogy of organisms through 
the study of isolated forms outside definite groups. 1 

His ardour in his work attracted the attention of 
several German scientists, one of whom introduced 
him to the celebrated botanist Cohn, who soon became 
interested in him. During the walks which they took 
together, they held scientific conversations full of 
interest for the youth. Cohn advised him to work 
under the celebrated zoologist Leuckart. Elie received 
this counsel with enthusiasm, but there was a great 
difficulty, which was the lack of money to prolong 

1 He made researches on a very singular annulate worm, the Fabricia. 


his stay abroad. He did not wish to ask for more 
from his parents and decided on the following plan, 
which he expounded in the following letter to his 
mother, the constant confidante of all his aspirations : 

HELIGOLAND, Aug. 12, 1864. 

DEAR MAMMA, ... I am thinking of staying here another 
month, after which I shall go (at least that is my desire) for ten 
days toGiessen, where there will be a General Congress of natural- 
ists and physicians from the whole of Europe. This Congress 
tempts me so much that I want to do my utmost to attend it. 

Besides all the scientific benefit that I shall reap from 
conversations with scientists, I can also study Professor 
Leuckart's rich collections. This would complete the studies 
which I am successfully pursuing at the seaside. 

In order to realise my ardent wish to profit by such treasures, 
I must remain three weeks longer at Heligoland, travel to 
Giessen and live there for ten days ; all that out of the money 
which was to keep me here until the 26 Aug. only. . . . 
Therefore, instead of living in the hotel, I have taken a room 
at a fisherman's, for half the price ; instead of a dinner and 
coffee I eat what I can get and I only spend 90 centimes a 
day for my food. (Food is dear, as all the provisions come 
from Hamburg and from England.) Instead of changing my 
linen two or three times a week, I only do so once or twice, 
which allows me to spend less on laundry. 

The money thus economised, together with the sum which 
I had put aside for my first installation at Petersburg, con- 
stitutes a sufficient capital to provide the following joys and 
advantages : 1, I shall stay three weeks longer at the seaside, 
which will allow me to get on with my researches and to 
increase my collections ; 2, I shall attend the Congress ; 3, 
I shall be able to study Leuckart's collections and take advan- 
tage of his books and counsel. 

I beseech you not to look upon this description of my 
present life as a complaint or a murmur ; on the contrary I 
am delighted to procure so many advantages at so small a 


cost ; I am happy, too, to be able to assure you in all conscience 
that I am not wasting the money that you have found for me 
with so much care and affection. I only wish I could find 
myself oftener in the same conditions. 

Please also believe that my health is in no way suffering 
from my work. I give you my word that until now I have not 
had a single headache. 

Moreover, I do not think work is at all detrimental to 
health ; I see here several German scientists who could fell 
an ox with their fist ! Altogether I beseech you not to be 
anxious on my account ; you have quite enough painful pre- 
occupations without that, and I am in such excellent circum- 
stances that there really is nothing to worry about. I kiss 
your hands many times. 

Yours affectionately, 


P.S. Write to me oftener. Every word from you is so 
precious to me ! 

He did not tell his mother that he never had 
enough to eat. Neither did he wish Cohn and his 
other acquaintances at Heligoland to notice it, and 
he carefully concealed his style of living. 

He went to Giessen for the opening of the Natural- 
ists' Congress and read with success two papers 
dealing with his researches at Heligoland. Engel- 
mann (who was to become well known as a physio- 
logist) and he were the youngest members of the 
Congress, and their extreme youth attracted general 
attention. Elie at last made Leuckart's acquaint- 
ance ; he was charmed by him and definitely decided 
to begin at once to work under his direction, and, as 
his stay abroad had thus to be prolonged, he asked 
and obtained a bursa from the Russian Ministry of 
Public Education. 

The results of his researches at Heligoland had 


led him to suppose that the Nematodes (of the worm 
type) formed an independent group ; he now pro- 
posed to settle that question. Leuckart allowed him 
to work in his laboratory during his absence for the 
holidays ; Elie immediately set to work and dis- 
covered a very curious and quite novel case of alter- 
nation of generations; hermaphrodite and parasitic 
Nematodes giving birth to a free bisexual generation. 

Delighted with his discovery, he hastened to com- 
municate it to Leuckart, who was incredulous at first 
but had to give way to evidence when Elie showed 
him all the intermediary stages. Still the German 
scientist was obviously annoyed that this discovery 
should have been made in his absence and inde- 
pendently from him. He proposed to the young 
man that they should continue researches in colla- 
boration and publish a joint memoir. Elie accepted 
joyfully. In his ardour he worked too much, and 
fatigued his eyesight so that he was forced to limit 
his microscopical researches to a few hours a day, and 
Leuckart advised him to take a rest. 

It happened that Elie's brother Leo had just settled 
in Geneva and invited him to stay with him ; Elie 
started to join him. The brothers had not met for a 
long time. Leo had been travelling and had resided 
in many different places. He was an extraordinarily 
gifted man, impulsive, brilliant, and artistic, but rest- 
less and incapable of adhering to a steady course of 
action ; he scattered his activities and did not there- 
fore produce all that his rich nature was capable of. 
He had a remarkable gift for languages ; he knew not 
only a number of European languages but also several 
Oriental languages, having been in the East, where he 
had occupied a post of agent in navigation and com- 


merce. He afterwards lived in Italy, took an active 
part in the Garibaldi movement and was wounded. 
A clever painter, he also had real literary talent ; 
handsome, witty, agreeable, he was a most attractive 
personality. Elie had great affection for him. 

He found him surrounded with young men and 
studying a map. They were discussing the acquisi- 
tion of a piece of ground in Italy in order to found 
a socialistic community, and Leo, who knew the 
country, was to choose the locality. Elie was at once 
made acquainted with the political questions of the 
day ; the young scientist was unfavourably impressed, 
for the whole reduced itself to party questions and 
dogmatic discussions founded on hollow grounds. 
Accustomed as he already was to positive scientific 
methods, vague and arbitrary theories could not 
satisfy him. 

On the other hand, he was deeply impressed by 
the personality of the celebrated socialistic Russian 
writer, Herzen, who resided in Geneva at that time. 
The young revolutionaries considered him as too 
literary and too much of a theoretician ; they them- 
selves yearned for a direct-action policy. Leo Metch- 
nikoff, however, admired him fervently. Meetings 
often took place in Herzen's rooms ; he used to read 
to his guests with wonderful effect his yet unpublished 
manuscript Passe et pensees. A great and powerful 
figure, the superiority of his intelligence was almost 
crushing, while his sparkling wit and the nobility of 
his whole being endowed him with an incomparable 
and irresistible personal charm. Metchnikoff often 
said that no man had left a deeper impression on his 
life. As a politician, however, he had not the same 
prestige in his sight. 


This sojourn in a revolutionary centre interested 
him much, but had the result of confirming his con- 
viction that science was immeasurably superior to 
politics, and he congratulated himself on the path he 
had chosen. After he had rested, he started to return 
to Griessen and stopped at Heidelberg, a centre for 
Russian students who gathered around Helmholtz, 
Virchow, and Bunsen. He hurried to the library in 
order to see scientific periodicals ; one of the first that 
came under his eyes was a number of the Gottingen 
News, containing a memoir by Leuckart on the Nema- 
todes which they had studied together ; Leuckart 
described, in his own name, their common researches 
and also those personal to the young man, whom he 
only mentioned incidentally. Elie was shocked and 
indignant. On his return to Giessen he tried to obtain 
an explanation from Leuckart but in vain ; the latter 
eluded his questions and gave him no answer. 1 

In his despair, the youth confided in Glaus, a pro- 
fessor of zoology whose acquaintance he had made 
at the Congress, who told him that Leuckart was in 
the habit of such dealings, and urged Elie, as an inde- 
pendent stranger, to reveal the fact. He pressed this 
with so much insistence that Elie ended in following 
his advice ; he sent an article stating the case to 
Dubois-Reymond's journal. He then departed from 
Giessen without taking leave of Leuckart. 

Having had a bursa of 1600 roubles a year granted 
him for two years by the Russian Ministry of Public 
Instruction, he was able to undertake a journey to 
the shores of the Mediterranean in order to pursue 
his researches. 

1 All this episode was described by Metchnikoff in 1866 in a separate 
publication with great restraint and in a very moderate tone. 


He had heard of a very talented young zoologist, 
Alexander Kovalevsky, who also knew him by hearsay 
and had written him a letter full of enthusiasm con- 
cerning the rich Mediterranean fauna and the facilities 
for work in Italy. He therefore went to Naples on 
leaving Giessen. Though the journey in itself had 
but a secondary attraction for him, he had expected 
to receive a strong impression ; but his imagination 
had painted such grandiose pictures of the country 
that he had to cross, that the reality disappointed 
him, and Italy, like Switzerland on a former occasion, 
fell very far short of his expectations. He stopped 
at Florence, which made but a poor impression 
on him. Museums fatigued him, for he saw a great 
deal too many works of art all at once without 
any previous preparation. Architecture and the 
plastic arts in general did not take any hold of him. 
During his rapid journey he only saw the country 
quite superficially and had no time to become im- 
pregnated with its beauty. He therefore hastened 
towards Naples, where his work and Kovalevsky 
attracted him far more. 

He found in Kovalevsky a young man with shy 
but cordial manners and the clear sweet eyes of a 
pure child, obviously an idealist. He had for science 
an absolute cult, the sacred fire of the worshipper ; 
no sacrifice was too great, no difficulty too repellent 
for his ardour. On a closer acquaintance, the small, 
timid young man proved to be a hard fighter where 
science was concerned. The two young men formed 
an excellent impression of each other, and a friendship 
was started between them which was to last a life- 
time. Though very different from each other, they 
met on common ground, a passion for science. They 



worked with the greatest energy, going together on 
zoological excursions, exchanging their ideas, dis- 
cussing their aspirations ; a similarity of tastes lent 
great attraction to their friendship. 

At Giessen, Elie had read Fritz Miiller's For 
Darwin, a book which had a decisive influence on the 
future direction of his researches. Fritz Miiller, in his 
embryological works on certain crustaceans, had been 
the first to confirm in a concrete manner Darwin's 
evolutionist theories ; he had thus demonstrated that 
it was chiefly in embryology that precious indications 
were to be found concerning the genealogy of organ- 
isms. 1 Under the influence of this work, Elie, who 
until now had limited himself to introductory re- 
searches, resolved to concentrate all his efforts on the 
comparative embryology of animals. He started to 
work in that direction, and his researches confirmed 
him more and more in the opinion that the key of 
animal evolution and genealogy was to be sought for 
in the most primitive stages, in those simple phases 
of development where no secondary element has yet 
been introduced from external conditions. In those 
primordial stages, essential characters, common to 
all, reveal the analogy and connections between 
animals from different groups. 

Every animal begins by being unicellular, for the 
egg-cell, the reproducing cell, common to all, corre- 
sponds to a unicellular being. It is only after fecunda- 
tion, when it has become an ovum, that this first 
cell evolves by dividing itself into consecutive 
segments, each of which is a new cell. This pheno- 
menon is analogous with the multiplication of uni- 

1 In later years Metchnikoff often dwelt on the fact that Fritz Miiller 
was not fully appreciated and that it was he who had most efficaciously 
contributed to the confirmation of Darwinian theories. 


cellular beings through division ; only, those segments 
of the ovum do not separate but constitute a whole 
under the aspect of a hollow sphere, called a blastula, 
which is the first manifestation of a multicellular 
being. This blastula is formed of superposed layers, 
each of which gives birth to specialised organs in the 
embryo. The outside layer, or ectoderm, produces 
teguments and the nervous system ; the internal layer, 
or endoderm, gives birth to endothelial cells, the digestive 
and internal organs ; between those two layers comes 
a third, intermediary layer, the mesoderm, from which 
the skeleton is developed and also the muscle and 
blood tissues. 

The evolution of these layers in Vertebrates was 
well known, but very little so in Invertebrates, though 
it is only through the development of inferior forms 
that the origin and general evolution of living beings 
can be elucidated. That is why, during many years, 
the principal theme of MetchnikofTs researches was 
the comparative study of the embryonic layers of 
inferior animals and the ulterior fate of their con- 
stituting elements. By following this train of thought, 
he was able to demonstrate that the development of 
lower animals takes place on the same plan and 
follows the same laws as that of higher animals ; 
thus, that there is a real communion between all 
living beings, which is the concrete confirmation of 
the theory of evolution. 

By their work, Kovalevsky and Metchnikoff con- 
tributed to the foundation of Comparative Embryo- 
logy. The comparative study of cells produced from 
the divers embryonic layers, and observations on the 
ulterior development of the functions of those cells, 
gradually led Metchnikoff to his theory of phagocytes 


and to pathological biology. An uninterrupted thread 
can be followed right through his life-work, from the 
beginning until the end. 

In spite of his absorbing work he took great 
interest in his surroundings, and during this first stay 
in Italy he became acquainted with two interesting 
personalities, Bakounine the anarchist and the cele- 
brated physiologist Setchenoff. Both resided at 
Sorrento. Kovalevsky and Metchnikoff, who greatly 
desired to know them, decided to call on them, after 
much hesitation. 

Bakounine, a giant with a leonine head and a 
thick mane of grey hair, struck them as being a fiery 
enthusiast but an intolerant sectarian, easily roused ; 
for instance, any small and unimportant local meeting 
was enough for him to predict an imminent revolution 
in Russia. His theories were epitomised in these 
words, " We must not leave stone upon stone " ; but 
when asked what should be built up on those ruins 
he could only say, " We shall see later." Elie looked 
upon him as a force powerful by its fire and vitality, 
but thought his mind neither judicial nor profound. 

Very different was the impression produced on 
him by Setchenoff. He carried great weight through 
the depth of his intelligence, his persuasive eloquence 
and general thoroughness. He was of a Mongol type 
and his features were plain, but his splendid eyes, 
deep and intelligent, shrewd and yet kindly, illumined 
his face with an unforgettable inward beauty. When 
Elie went to see him, it was with the uneasy feeling 
that his own knowledge of chemistry and physics was 
very restricted, having been very superficially acquired 
during his rapid passage through the University. 
In spite of this cause for bashfulness, a mental com- 


pact and exchange of ideas was immediately estab- 
lished between the two, and a sympathy was born 
between them which developed into a lifelong friend- 
ship. Elie expatiated upon his plans for the study of 
the embryology of inferior animals from the evolution 
point of view, and received from the older scientist 
much encouragement, for which he never ceased to 
be grateful. 

He worked a great deal during this first stay at 
Naples, in spite of periods of great fatigue. As a 
relaxation, he plunged into philosophical reading. 
After Kovalevsky's departure, he joined Bakounine's 
circle, the members of which took their meals in a 
restaurant which rejoiced in the sonorous name of 
Trattoria della Harmonia. In the autumn of the year 
1865, a cholera epidemic broke out in Naples. Every 
one was nervous and depressed, and this general 
depression was increased still more by some of the 
customs of the country continuous lugubrious 
church bells, funeral processions in which penitents 
took part, carrying smoking torches and wearing 
hoods over their heads with holes for their eyes, etc. 
Elie, on whom the epidemic had made a great impres- 
sion, was even more disturbed by the death of one of 
the members of their little circle, a popular English- 
woman, liked by everybody. She had no fear of 
cholera and was bright and merry. But one day she 
did not come to the Trattoria della Harmonia ; she had 
been struck by the scourge and was dead the next day. 

Elie was so struck by her death that his nerves, 
already very tense, gave way and he left Naples, being, 
moreover, worn out with overwork. 

He started for Gottingen, for he wanted to begin the 
study of Vertebrates under the direction of Professor 


Keferstein. Keferstein straightway gave him a valu- 
able lizard specimen to anatomise. Elie was not 
good at technique, on account of his nervous tem- 
perament ; he used occasionally to lose his patience 
and his temper, to that point that he flung his material 
across the room. It happened so on this occasion ; 
having completely wasted the valuable lizard, he con- 
ceived a still greater horror of technique and soon left 
Professor Keferstein for Henle, the celebrated anatom- 
ist. He worked with him for a short tune at the 
histology of frogs' kidneys, a subject chosen by the 
Professor. Soon the young man realised that he was 
no longer capable of submitting to school discipline 
and resumed his independent researches. When he 
had to do with those problems which absorbed him 
he was always able to conquer his aversion for tech- 
nique and to do what was required. He studied the 
embryology of the green-fly from the genealogical point 
of view, and went to Munich for the summer term 
in order to work with the celebrated zoologist von 
Siebold, a typical and venerable old German scientist. 
The latter was too old already to be troubled with 
pupils, and Elie studied his insect embryology indepen- 
dently ; however, he visited the old man assiduously, 
and they had long scientific conversations. Their 
relations were always extremely cordial, and they 
even kept up a regular correspondence for many years. 
During his stay in Germany, music was the young 
man's only recreation. He did not play any instru- 
ment ; his parents, discouraged by the failure of their 
elder children, had not had him taught, and besides, 
his precocious vocation would have left him no time. 
Yet he certainly had a natural talent for music, which 
he passionately loved. He could only whistle, but 


with that feeble means succeeded in reproducing com- 
plicated compositions. Having assiduously attended 
excellent concerts, he had made himself thoroughly 
acquainted with classical music, and Beethoven and 
Mozart always remained his favourite composers. 
His stay in Germany taught him to appreciate the 
great capacity for work of the scientists of that 
country ; he admired the organisation of their labora- 
tories, allowing every force, great or small, to be 
utilised and making useful collective work possible 
in those complicated researches which demand the 
collaboration of divers specialists. On the other hand, 
he felt a great aversion for the manners and customs 
of German students. Their corporations, duels, and 
long sittings in beer-houses were distasteful to him ; 
he could not understand how these coarse " Burschen " 
could become transformed into cultivated intellec- 
tuals and respectable scientists. People to whom he 
expressed this wonder merely said, " Youth must 
have its fling. ..." Moreover, scientists themselves 
were not particularly courteous to each other. More 
than anywhere else personal questions held a fore- 
most place, and kindliness was rare between colleagues. 
After staying some time in Munich, Elie returned 
to Naples, war having broken out between Northern 
and Southern Germany. This time, in order to spend 
less on the journey, he took a steamer at Genoa, but 
with fatal results, for a storm was raging ; he suffered 
a great deal, and, when he reached Naples, violent fits 
of giddiness made him incapable of doing any work at 
all for some time. Cholera reappeared, and the land- 
lady of the rooms he shared with Kovalevsky died of 
it. Much depressed, the two started for Ischia, but 
Elie soon realised with terror that he was not yet well 


enough to work ; in order to recover quickly, he went 
to Cava, a pretty little place, renowned for its salu- 
brious climate. 

There he met Bakounine again, and they saw a 
good deal of each other in a friendly way. Bakou- 
nine nicknamed him " Mamma " because of his almost 
maternal attentions, a nickname which, for the same 
reason, was given him later, quite independently, by 
other intimates. Yet, though their relations were 
cordial and even affectionate, there was not really 
much in common between the two. Elie thought 
Bakounine's ideas superficial, and disliked his sectarian 
mentality ; they ultimately drifted apart. 

His health having gradually recovered owing to the 
rest, he returned to Naples in the autumn, after the 
epidemic had abated, and at last resumed his work. 

Whilst studying the history of the development of 
Cephalopoda he found that they had embryonic 
layers similar to those of Vertebrates ; this was the 
first time that the fact was established. It was ex- 
tremely important, for it constituted a concrete and 
indisputable proof of the existence of a genetic 
connection between inferior and superior animals. 
Metchnikoff chose this subject for his thesis, and, 
having completed his researches, he returned to 
Russia in 1867. 

By this time he had made great use of his three 
years' stay abroad. Though he had not showed 
himself a docile pupil, yet he had become initiated 
into the organisation of scientific work in Germany ; 
he had carried out independent researches and had 
been able to choose with full knowledge the future 
path of investigations which he was to pursue for 
many years in the field of Comparative Embryology. 


Already the observations he had made had in 
themselves a real importance. For instance, his 
studies in divers specimens of the worm type, a type 
which offers very heterogeneous forms, had permitted 
him to establish links of continuity between certain 
groups among them. Whilst studying those animals 
at Giessen in 1865, he had discovered the capital fact 
which proved to be the starting-point of all his future 
work the intercellular digestion of an inferior worm, 
a land planarian, the Geodesmus bilineatus. He had 
compared this digestion with that of the superior 
Infusoria and had seen in it one more proof of the 
genetic connection between the type of the Protozoa 
and that of worms. 

He did not then realise the full bearing of this 
observation, which really constituted the basis of his 
future phagocyte theory ; this was only to appear 
eighteen years later. 

He had also made researches on numerous speci- 
mens of insects and on the scorpion, establishing the 
fact that they all had embryonic layers ; he concluded 
that he was " entitled to extend the theory of em- 
bryonic layers to Arthropoda." 

Finally, he had discovered embryonic layers similar 
to those of the Vertebrates in inferior Invertebrates, 
the Cephalopoda (Sepiola). This established a link 
of continuity between the higher and lower animals. 


Petersburg Baer prize Return home Friendship with Cienkovsky 
Odessa Naturalists' Congress at Petersburg Departure from 
Odessa Zoological Lecturer's Chair at Petersburg Messina 
Enforced rest Reggio Naples Controversy with Kovalevsky 
Visit to the B. family Mile. F6dorovitch Educational questions 
Difficulties of life hi Petersburg. 

DURING his stay abroad, Metchnikoff had successfully 
carried out several researches, and this allowed him 
to apply for a post of docent at the new University of 
Odessa, which he had chosen on account of its proxi- 
mity with the sea and its marine fauna. Whilst 
awaiting the result he went to Petersburg in order to 
pass his thesis and to prepare himself to become a 
professor. He received a pleasant welcome, for his 
lively and sociable disposition had made him many 
friends. The brothers Kovalevsky, with whom he was 
already on friendly terms, offered him hospitality ; 
he also made the acquaintance of Professor Beketoff, 
and soon became a member of his family circle. 

He was well received everywhere, for his scientific 
precocity excited general interest. He was even 
elected magister x by the Faculty, without having to 
pass an examination, on account of the work he had 
done. He and Kovalevsky halved Baer's first prize, 
and they were invited and treated with the utmost 
kindness by Baer himself. Metchnikoff had certainly 

1 A degree preceding that of Doc.Sc. 


entered upon a successful phase ; his friends nick- 
named him " the star." As soon as he was made a 
magister, he received his appointment at the Odessa 
University, and, the holidays drawing near, he was at 
last able to return to his home. Needless to say how 
joyfully and lovingly he was received by his family. 
He spent two months with them, utilising his leisure in 
preparing himself to teach. 

In his hurry to arrive in Odessa in good time in 
order to take his bearings before starting his lectures, 
he went there much too soon and found nobody at 
the University ; he then decided to go to the Crimea 
for some preliminary studies on the fauna of the Black 
Sea. Before long, he made the acquaintance of the 
celebrated botanist Cienkovsky, who invited him to 
stay in his villa. Though the scientist was already 
46 years old and Elie only 22, they soon became fast 
friends. Cienkovsky was a man of great European 
culture ; passionately fond of science as he was, his 
critical mind submitted everything to a close analysis. 
He took great interest in young Metchnikoff and 
showed him a marked predilection, but that did not 
prevent him from criticising him severely. He re- 
proached him with a lack of self-control, and undertook 
the paternal task of civilising the impulsive, fiery, 
sometimes even violent young man. He preached 
to him tolerance towards the opinions of others, a 
strict self-discipline, and the absolute necessity of 
bowing to certain social conventions against which 
Elie blindly rebelled. Cienkovsky acquired great 
prestige in his young friend's eyes ; years later, even, 
Metchnikofi took pleasure in quoting his axioms and 
in trying to conform with them. 

He worked with ardour during his stay in the 


Crimea ; though the heat was great, 50 C. (122 F.) 
in the sun, he undertook zoological excursions 
and surprised every one by his endurance and 

At the end of the holidays he returned to Odessa 
and began his professorate with much zeal and 
success. His lucid, living lectures stimulated his 
pupils, third-year students, who were all older than 
himself. Friendly relations soon reigned between 
them and their young lecturer ; he organised practical 
studies, and his laboratory became a very active 
centre of work. 

Thus everything was going well, and perhaps he 
might have remained at Odessa for a long time if it 
had not been for the following incident, due to his 
passionate and intolerant disposition. A Congress of 
Russian naturalists was to take place in Petersburg 
at the end of the year 1867. Elie eagerly wished to 
attend it as a delegate and took steps for that purpose ; 
this brought him into conflict with his chief, who 
desired the mission for himself. Knowing that the 
old Professor had no real scientific interests, Elie 
thought himself justified in insisting, and counted 
upon Cienkovsky's support, but the latter was of 
opinion that the younger man should give way. Elie, 
becoming more and more excited, lost all sense of 
proportion and committed the grave error of telling 
his pupils about what he considered a serious injustice. 
The latter, out of sympathy for their young lecturer, 
hooted the old Professor, which naturally embittered 
the quarrel. However, all the agitation ended in both 
zoologists being sent to the Congress in the quality of 

When he reached Petersburg, Elie hurried to the 


house of his friends B , who received him with 

open arms ; it was a great joy to him to find himself 
in friendly surroundings after the recent strife. Im- 
pulsive and impressionable as he was, the disagree- 
able incidents he had traversed made him yearn to 
leave Odessa, a desire which was to be promptly 
realised. His communications had great success at 
the Congress ; the President even invited him to 
read a paper at the general meeting ; but, though 
strongly attracted by this proposal, which would 
have allowed the young scientist to expose his ideas 
on the comparative development of the embryonic 
layers, he refused it, considering that that complicated 
question was not yet sufficiently matured. 

Nevertheless, the Congress had brought him into 
prominence and was the cause of his obtaining a 
Professorship of Zoology at Petersburg. Moreover, 
he had the additional good fortune of being given a 
scientific mission and went abroad to work until the 
autumn term. 

He went to Naples in the spring of 1868, thinking 
to find Kovalevsky there, instead of which he found 
a letter from his friend awaiting him. The latter had 
had to go to Messina for urgent embryological work 
and begged Elie to look after his wife and new-born 
child. Metchnikoff did so most willingly until he was 
able to send them off to Messina. He himself followed 
soon after, for Kovalevsky wrote him that zoological 
specimens and conditions of work were far better at 
Messina than Naples. This time, Metchnikoff under- 
took the study of Sponges and Echinodermata. The 
two friends worked unceasingly, but Elie's sight was 
too weak for such excessive fatigue ; he was again 
obliged to interrupt his studies for a while, and during 


that period of enforced rest he felt for the first time 
the need of a sentimental affection in his life. 

He dreamed of a helpmeet who would conform with 
his tastes. At Petersburg he had become very fond 
of Professor B.'s young daughters, the eldest of whom 
was about thirteen years old, and he wondered if he 
could not train one of those little girls to become the 
realisation of his ideal. He was too active by nature, 
however, to linger very long over reveries or over 
a prolonged rest ; he therefore undertook a short 
journey through Reggio and Calabria, on his way 
towards Naples. 

His eyesight being now restored, he began work 
again as soon as he arrived. This period, however, 
was not a pleasant one : to begin with, he obtained 
in the study of Ascidia a result which differed con- 
siderably from that obtained by Kovalevsky, 1 and 
this scientific controversy grieved and preoccupied 
them both. Besides, Elie's nerves suffered from his 
constant anxiety about his eyes, the tropical heat and 
the noisy life of Naples. Incessant serenades used to 
keep him awake at night, and, on one occasion, his 
exasperation reached such a point that he poured a 
bucket of water over the head of some persistent 
musicians. Tired with all these things, he left Naples 
for Trieste, where he carried out successful researches 
into the transformations of Echinodermata, from the 
point of view of Comparative Embryology and genetic 
connections between inferior animals. 

Having obtained results which interested him, he 
returned to Russia and joined the B. family in the 

1 The latter affirmed that the nervous system of Ascidia originated from 
the upper layer, whilst Elie believed that it was the lower layer which gave 
birth to it. It was Kovalevsky who was right, as Elie himself declared 


country, near Moscow. Their young friend Mile. 
Fedorovitch, whom he had already met in Petersburg, 
was staying with them, and she and Elie became very 
good friends. His affection for the B. children led 
him to ponder over general educational questions. 
He was struck for the first time by the lack of harmony 
in human nature, which was due, he thought, to the 
considerable difference between the organism of the 
child and that of the adult, a difference which does 
not exist in animals to the same degree. 1 As soon 
as he returned to Petersburg he tried to study this 
subject, and made comparisons between the brain of a 
man and that of a dog at various ages, but without 

He was not long in realising that the conditions 
of work in his new post were extremely unsatisfactory. 
He had no proper laboratory and had to work between 
two specimen cases in a non-heated zoological museum ; 
there was no room for practical work. All his enthusi- 
asm, all his aspirations towards scientific activity and 
rational teaching struck against indifference, lack of 
organisation, and lack of means. He protested with 
his usual vehemence, but could obtain nothing ; being 
equally unable to adapt himself to his uncongenial 
surroundings, he found himself getting more and more 
discontented and unnerved. Moreover, his every- 
day life was most uncomfortable, for he wished to do 
without servants, on principle and in order to econo- 
mise, and to do his household work himself ; but he 
soon tired of taking the necessary care of his rooms, 
which became a regular chaos. He left off preparing 
his own meals and went out for them to an inferior 

1 He ultimately developed these considerations in a paper entitled 
Education from an Anthropological Point of View, of which mention will 
be made hereafter. 


restaurant in the neighbourhood. Yet, in spite of 
all his efforts and privations, he never seemed to make 
both ends meet. He resigned himself to giving lessons 
at the School of Mines in order to increase his resources; 
the school was a long way off, he had to walk the 
distance in the coldest weather in order to lecture 
to students who did not interest him. The work 
wearied him without giving him any moral compen- 
sation. Altogether, the life in Petersburg, on which 
he had founded great hopes, brought him nothing 
but disappointments and made him become more 
and more pessimistic and misanthropical. 


Slight illness Engagement to Mile. Fedorovitch Marriage Illness 
of the bride Pecuniary difficulties Spezzia Montreux Work in 
Petersburg University The Riviera Ccelomata and Actelomata 
St. Vaast Panassovka Madeira Mertens Teneriffe Return 
to Odessa Bad news, hurried journey to Madeira Death of his 
wife Return through Spain Attempted suicide Ephemerida\ 

IT was only in the house of his friends the B.'s that 
Elie felt at his ease. He was devotedly fond of 
their children, whom he used to take for walks on 
Sundays and to the theatre now and then ; he was 
always ready to read to them and to indulge them in 
every possible way. 

He continued to entertain the dream of marrying 
one of them some day, and was particularly interested 
in the eldest, a girl of thirteen, intelligent, gifted, and 
lively ; however, as he knew her better, he realised 
the incompatibility of their respective tempers, an 
incompatibility which brought about frequent dis- 
putes. These were generally smoothed down by a 
mutual friend, Mile. Fedorovitch, who invariably 
showed Elie a marked and cordial sympathy. He 
became ill at this juncture and she nursed him with 
a devotion which brought them together even more, 
as will be seen from the following letter to his mother : 

DEAR MOTHER I Lave just had an inflammation of the 
throat which lasted two weeks ; it is quite gone now and I 
would not even have mentioned it to you if it had not been 
connected with what follows. 

65 F 


When I fell ill, the B.'s, knowing me to be alone and uncared 
for, brought me to their house. During my stay with them, 
I acquired the conviction that my darling little girls did not 
love me, especially the eldest, who interested me even more 
than her three sisters. . . . The dreams I told you of have 
vanished ! 

It was a grief to me, for, apart from my scientific interests, 
I cherished them more than anything. I have no acquaint- 
ances and do not require any, but I long to have some one 
with me to whom I could become attached and who could 
share my pleasures and leisure. 

My grief would have been greater still if I had not seen 
that Ludmilla Fedorovitch, whom I mentioned to you this 
summer, showed me much sympathy in all my troubles. 

We were already very good friends, and have now drawn 
nearer together ; who knows ? perhaps the 800 roubles which 
are going to be added to my salary will be very useful. 

I will keep you informed of everything, dear Mother, for 
I am sure of your sympathy ; I love you better than the whole 
world and I have full confidence in you. 

Au revoir, dear Mother, I kiss your hands. Your 


Mile. Fedorovitch became ill in her turn ; the 
sympathy which Elie showed her on this occasion 
brought them still nearer to each other, and he soon 
decided to marry her. He informed his mother of 
this ; much alarmed, she tried to dissuade him, for 
she feared that by marrying a girl in delicate health, 
her son would be assuming too heavy a task in his 
difficult circumstances. 

He answered as follows : 

I received your letter to-day, dear Mother. It grieves 
me very much. My project inspires you with doubt, you 
counsel prudence and, though you say you believe me to be 
reasonable, yet you fear that I am acting on an impulse. If 
I really am reasonable, why fear a blind impulse ? On the 


other hand, if I am blindly carried away, it is not likely that 
I shall listen to reason. 

I did tell you that I had great affection for the B. girls, 
and it was true. But did I ever tell you that they had the 
same for me ? You are mistaken in thinking that I did not 
like Ludmilla Fedorovitch at first. I was not in love with 
her but we were very good friends, and whilst I did not con- 
sider her as my feminine ideal, I was sure of her absolutely 
honest, loyal, and kindly disposition. The very fact that I 
knew Ludmilla for a long time before I thought of marrying 
her, should prove to you that there is some chance of my 
being neither blind nor partial. 

Her love for me is beyond doubt, as you will see when you 
know her. 

I also am very fond of her, and that is a solid basis for 
future happiness. 

Yet I will not answer for it that we shall spend our life 
like a pair of turtledoves. A rosy, boundless beatitude forms 
no part of my conception of the distant future. 

Yet I do not see the necessity of waiting till I become a 
thorough misanthrope, and I am already inclined that way. 

Please do not believe that, if I do not dream of a rosy 
happiness it is that I feel none at all ; that is not the case ; 
I am in a happy medium. 

I like Ludmilla and I feel comfortable with her ; but at 
the same time I preserve the faculty of feeling every trouble 
and worry in life. I do not at all think that it is enough 
to love in order to be happy. Therefore I have begun to take 
steps to obtain a Professor's chair, and I am very desirous 
of being successful in that financial operation. 

Soon after that, he wrote the following letter to his 
mother : 

DEAR MOTHER In my last letter I had already spoken 
to you of Ludmilla Fedorovitch. I can now give you infor- 
mation about her which will surely interest you. 

She is not bad-looking, but that is all. She has fine 
hair ; her complexion is not pretty. We are about the same 


age, she is a little over 23. She was born at Orenburg ; then 
she lived for a long time with her family at Kiahta (Siberia), 
after which she was abroad for nearly two years and finally 
settled in Moscow. Ludmilla, or Lussia, was, as you remember, 
a very zealous intermediary between me and the B. girls to 
whom I was so attached. 

She loved me already then, though she said to herself that 
I had too much affection for the B. children ever to return 
her feelings. 

And she was perfectly right, as long as my affection for 
those children lasted. 

But, when it ceased, I naturally took more notice of Lussia's 
sympathy for me, and I am not surprised that I have acquired 
much affection for her. 

She has faults which must seem graver to me than to you, 
but what is to be done ? 

Fortunately she herself sees them. The greatest of her 
faults is a too great placidity, a lack of vivacity and initiative ; 
she adapts herself too easily to her surroundings. But, 
being placid, she is also firm ; she can bear a great deal whilst 
preserving complete self-control. She is extremely kind and 
good-natured ; I have not yet found a vulgar trait in her 

I have told you of her faults, you must therefore not 
think me partial if I find qualities in her. 

The fact is and I cannot forget it that always, when I 
had any kind of trouble, she soothed me by her attitude 
towards me. 

Even though I have dark previsions for the future (as you 
know, I am not given to seeing life through rose-coloured 
glasses), I cannot help thinking that by living with Lussia I 
should become calmer, at least for a fairly long time. 

I should cease to suffer from the misanthropy which has 
invaded me lately. 

I intend to have no children it is an embryologist who 
is speaking. On the contrary, I want to preserve the utmost 
liberty. Nevertheless, one must conform with certain legal 
conventions, which will probably take place in January. 


Lussia has no fortune, but we shall be entirely guaranteed 
by the increase in my salary. 

It is very regrettable that the event should be retarded by 
the customary formalities ; in any case it will certainly end 
by taking place. 

I beg you to write to me, dear mother that I love, anything 
that comes into your head a propos of my affair. 

Rejoice that I am now very happy and wish that it may 

I ask the same of Papa, whom I beg you to salute from me. 
I embrace you, dear Mamma, and I remain your very affec- 
tionate son, E. METCHNIKOFF. 

As Elie learnt to know his fiancee better, he became 
more and more attached to her. Their happiness 
seemed likely to be complete, but a cruel Fate had 
decided otherwise. The girl's health was not im- 
proving : her supposed bronchitis was assuming a 
chronic character. Yet tbe marriage was not post- 
poned, and the bride had to be carried to the church 
in a chair for the ceremony, being too breathless and 
too weak to walk so far. 

Elie did his utmost to procure comforts for his- wife, 
and hoped that she could still be saved by care and 
a rational treatment. It was the beginning of an 
hourly struggle against disease and poverty ; his 
means being insufficient, he tried to eke them out by 
writing translations. His eyesight weakened again 
from overwork, and it was with atropin in his eyes 
that he sat up night after night, translating. There 
was but one well-lighted room in his flat, and he 
turned it into a small laboratory for the use of his 
pupils ; his own researches he had to give up, his time 
being entirely taken up by teaching and translations. 

He hid his precarious position from his parents 
in order not to add to their heavy expenses nor to 


confirm their previsions concerning his marriage. His 
wife's illness, the impossibility of carrying on scientific 
work, the lack of friendly sympathy to which he 
thought himself entitled, all this weighed on him, 
making him bitter, suspicious, and distrustful ; he 
thought himself persecuted. The situation became 
intolerable and, in spite of his pride, he forced him- 
self to apply for a subsidy to take his wife abroad 
and to go on with his researches. Having obtained 
it in 1869, he immediately left Petersburg, which he 
now hated. 

Youth is elastic : the young couple started full 
of joy, gay as children, and ready to forget all their 
trials. Alas, it was not for long : having halted at 
Vilna in order that the patient should have a rest, 
she had an attack of haemorrhage of the lungs, to the 
great alarm of her husband, who nevertheless did his 
best to reassure her. They continued the journey as 
soon as her condition allowed it, only to be interrupted 
by another relapse. At last they reached Spezzia, 
chosen on account of the climate and the marine fauna. 

Little by little, Ludmilla Metchnikoff's health im- 
proved and her husband was able to resume work. 
He studied aquatic animals in view of the genealogy 
of inferior groups, and, amongst others, studied the 
Tornaria, which was believed to be the larva of the 
star-fish. However, to his astonishment, he ascer- 
tained that, in spite of great similarity, it was not 
the larva of an Echinoderm, but that of one of the 
Balanoglossi, of the worm type. This fact estab- 
lished a link between the Echinodermata and worms, 
a very important result from the point of view of 
the continuity of animal types. 

Metchnikoff felt his courage returning and also 


his natural high spirits. His wife, who was a clever 
draughtswoman, helped him with the drawings for 
his memoir, and both felt happy and contented ; this 
stay at Spezzia was a real oasis in their life. 

When the heat became excessive they went to 
Reichenhall, a summer resort prescribed by the 
doctor. There, Metchnikoff completed his previous 
researches on the development of the scorpion, and 
finally established the fact that this animal possesses 
the three embryonic layers which correspond to those 
of the Vertebrates. 

As his young wife's health was still too precarious 
to allow her to spend the winter in Kussia, Metchnikoff, 
obliged to return to Petersburg, installed .her at Mon- 
treux and asked his sister-in-law, Mile. Fedorovitch, 
to stay with her. The enforced separation deeply 
grieved the young couple, whose only consolation was 
daily correspondence. 

Metchnikoff resumed a life of hard work ; he was 
now an agrege at the Petersburg University and 
had to leave the School of Mines ; this diminished his 
resources, but at the same time he obtained an extra 
salary of 800 roubles as Extraordinary Professor. 
His position in the University was nevertheless very 
difficult, for his situation was coveted by different 
parties with which he had nothing to do. They 
wanted it for one of their adherents. His devoted 
friend Setchenoff, Prof essor of Physiology, then thought 
of proposing him to the Faculty of Medicine as a 
Lecturer in Zoology, and whilst Metchnikoff awaited 
the result of his efforts, he obtained leave to go to the 
seaside to do research work. 

He joined his wife and took her to San Remo 
and to Villafranca. Her health had improved and 


she was even able to take part in his work. He was 
engaged in studying Medusae and Siphonophora, 
animals which interested him, not only from the point 
of view of the origin of embryonic layers, but also 
from that of general morphology, for he was still 
pursuing the problem of genetic links between 
animals. He had already been able to prove the 
presence of embryonic layers in many inferior animals ; 
moreover, he had found, while studying the meta- 
morphoses of Echinodermata, the proof that the struc- 
tural plan, hitherto considered immutable, could 
become transformed in course of development. Thus 
the bilateral plan of the larva of Echinoderma becomes 
a radial plan in the adult. The structural plan there- 
fore is not an absolutely differentiating character, 
since specimens of the same type can show a different 
plan according to their stage of development. One 
of the genetic questions still unsolved was that of the 
body cavity. Always present in higher animals, it 
is totally absent in certain lower groups, such as 
Sponges, Polypi, and Medusae. It was being ques- 
tioned whether their dissimilar morphological char- 
acters did not correspond with a duality of origin 
separating animals which possessed a body cavity 
(Ccelomata) from those which did not (Aco3lomata). 

Kovalevsky, it is true, had observed that the 
body cavity of many animals (Amphioxus, Sagitta, 
Brachiopoda) took its origin in the lateral sacs of the 
digestive cavity, sacs which detach themselves from 
it in order to form the body cavity. But, in order 
to establish a genetic connection between those 
animals that have a body cavity and those which 
are devoid of it, it was necessary to show the homo- 
logy of corresponding organs in both groups. 


Through his researches on the development of 
Coelomata (Echinodermata) on the one hand and 
Acoelomata (Ctenophora and Medusae) on the other, 
Metchnikoff succeeded in proving that the lateral sacs 
of the digestive cavity which give birth to the body 
cavity of the Ccelomata (Echinodermata) correspond 
to the canals and vaso-digestive sacs of the Accelo- 
mata (Ctenophora and Medusae). The difference 
consists in that the latter do not detach themselves 
in order to form a body cavity, which is therefore 

The result of his researches satisfied Metchnikoff ; 
moreover, he began to feel again hopeful of his wife's 
recovery. The only dark spot was that Setchenoff's 
efforts had failed. Metchnikoff was not appointed 
by the Faculty of Medicine, for it was found advisable 
to replace the Chair of Zoology by one on Venereal 
Diseases. On the other hand, he was nominated for 
the Odessa University, supported by Cienkovsky and 
unanimously elected. 

As he only had to go to his new post in the autumn, 
he went for the summer to St. Vaast in Normandy 
to study Lucernaria ; unfortunately the stay was not 
a success ; the weather was cold and the sea very 
rough, which made the Lucernaria impossible to find. 
Life conditions were very difficult, all the male popu- 
lation being at sea and the women being in the fields. 
In order not to waste this journey he studied Ascidians, 
and found that he had previously been mistaken at 
Naples when he thought that the nervous system of 
those animals originated from the lower embryonic 
layer. Kovalevsky had been right in affirming the 
contrary, and Elie hastened to write to tell him so. 

St. Vaast, open to every wind, was not favourable 


to the patient, and Metchnikoff had to take her away. 
They went to Russia to stay with her parents and then 
to Panassovka. The doctors having advised a course 
of treatment by " koumiss," or fermented mare's 
milk prepared in a special way by the Tartars, Elie 
engaged a Tartar servant specially for that purpose, 
but in vain. In spite of every treatment, his wife's 
health was steadily growing worse. The cold at St. 
Vaast had been followed by such a dry heat in Russia 
that, in order to procure a little coolness for the 
patient, they had to spread wet sheets around her. 
She constantly had high temperatures and frequent 
attacks of haemorrhage. It was obvious that she 
must leave Russia, and Metchnikoff, obliged to rejoin 
his post at Odessa, asked Mile. Fedorovitch to go 
with her to Montreux. 

The separation was all the harder that all hope of 
recovery was beginning to wane. The patient, how- 
ever, had been told of the magical effect of Madeira 
in cases of tuberculosis, and she clung to the idea as 
to a plank of safety. Elie resolved to take her there. 
He set to work with renewed ardour in order to obtain 
the sum necessary for the journey ; in spite of all his 
self-denial, his normal resources would not have 
sufficed, and he had recourse to translations and 
literary articles. He had a theme ready, which he 
developed in a paper called Education from the Anthro- 
pological Point of View in fact a preliminary sketch 
of his ideas on the disharmonies in human nature. 
In it, he analysed the disharmonies due to the great 
difference of development between the child and the 
adult : whilst the young of animals are very rapidly 
able to imitate the adults and to live like them, the 
man-child is incapable of it. His brain, especially in 


civilised races, demands a long period of development 
in order to equal that of the adult, whilst certain 
instincts in the organism mature, on the contrary, long 
before their function is possible. Moreover, a child's 
sensibility is extremely developed whilst his will is 
by no means so. These causes provoke suffering and 
a series of regrettable consequences. 

Apart from frenzied efforts and unceasing labour, 
Metchnikoff was going through a painful moral crisis, 
due to the impossibility of making his conduct accord 
with his convictions. Party intrigues continued to 
be rife at the Odessa University : Poles were being 
persecuted by Nationalists ; one professor was refused 
admission on account of his Polish nationality, and 
Cienkovsky resigned by way of protest. Metchnikoff 
shared his views and longed to follow his example, 
but was prevented by his lack of means and felt it 
deeply. It also went against his conscience to ask 
for leave as frequently as his wife's condition made it 

She wished to see her parents once again before 
going to Madeira, and he took her to Russia for the 
last time : she never saw her family again. 

At last they were able to start. The long journey 
was very fatiguing, the sea voyage was rough, but, 
when she landed in Madeira, the patient thought herself 
saved. The very next morning Metchnikoff started 
feverishly on a voyage of discovery. Nature on the 
island was extremely beautiful ; alone the sight of 
numerous sick people reminded him of suffering and 
death. The words " a flower-decked grave " haunted 
his mind, and a growing despondency warned him that 
he had nothing to expect from this luxuriant spot. 
From the aspect of the rocky coast, beaten by the 


waves, he realised that the beach fauna must be very 
poor ; his only refuge, research work, was likely to be 
denied him. 

He was advised to hire a small house, which would 
be cheaper than a boarding-house, and he did find 
a pretty furnished villa with a garden ; it was beyond 
his means, but a young Russian named Mertens, who 
had been a fellow-traveller, proposed to share it with 
them. The arrangement proved highly satisfactory, 
and Mertens, at first merely an agreeable neighbour, 
became a close friend. 

Before leaving for Madeira, Metchnikoff had 
obtained a scientific mission and a subsidy from the 
Society of Natural Science Lovers of Moscow, and 
felt it a moral obligation to obtain some results. The 
scantiness of the marine fauna was a bitter disappoint- 
ment ; he had to fall back upon what little he found, 
and embarked on the study, hitherto unknown, of 
the embryology of Myriapoda. But this research 
work brought him a new source of torment instead of 
satisfaction : he could not master the technique, which 
proved to be very difficult, and this irritated him ; 
his failures disappointed him, made him vexed with 
himself ; his nerves, already strung to the highest 
point by suffering and anxiety, made the disappoint- 
ment unbearable. On the other hand, the external 
aspect of life formed a striking contrast with the state 
of his mind. A wealth of natural beauty, all flowers 
and perfumes, in an incomparable site, congenial sur- 
roundings and home comforts formed the frame for 
these two young lives, of which one was waning whilst 
the other was spent in a useless struggle to save it. 

MetchnikofFs natural pessimism was growing under 
the influence of these painful circumstances. His 


conception of life was a sombre one ; he said to himself 
that the " disharmonies " of human nature must in- 
fallibly end in a general decadence of humanity. He 
set forth his reflections in an article entitled The Time 
for Marriage, in which he discussed the following 
concrete fact : With the progress of civilisation and 
culture, the time for marriage recedes gradually, 
whereas puberty remains as early as before ; the 
result is that the time between puberty and marriage 
is becoming longer and longer, and constitutes a 
growing period in which there is no harmony. The 
statistics of suicides prove that there is a close con- 
nection between them and the period of disharmonies. 

Whilst he worked, his wife tried to make use of 
her leisure : she interested herself in poor children, 
sketched flowers, read novels ... life flowed peace- 
fully in spite of the underlying drama. 

Yet the thought that he was not fulfilling his 
obligations was intolerable to Metchnikoff. He 
thought of resigning and founding a small book-shop 
at Madeira in order to be independent and not obliged 
to leave his wife, but lack of funds made this plan 
impossible. In his search for new resources, he went 
to Teneriffe to look for a subject for an article. He 
met with several disappointments on this trip ; yet 
he saw the Villa Orotava, with its celebrated giant 
dragon-tree, which had already then been brought 
down by a storm. He also visited the Caves of the 
Guancios, the primitive inhabitants of the Canary 
Islands. Having gathered the necessary observations, 
he hastened to return to Madeira, where months passed 
without bringing any change. 

The book-shop idea was abandoned as being im- 
practicable and Metchnikofi had to return to Odessa, 


asking his sister-in-law to come to Madeira in his 
place. When she had arrived, he confided the two 
girls to Mertens and to the care of the devoted Dr. 
Goldschmidt, and went away conscious of the useless- 
ness of his efforts and more deeply pessimistic than 

When he reached Odessa, in October 1872, he 
found there his friend Setchenoff, whom he had pre- 
viously proposed for a Physiology Lecturer's chair, 
and whose affection was a great comfort to him at 
this sad time. The correspondence between him 
and his wife during that period is full of an infinite 
tenderness, as if they felt the supreme separation 
coming near, and yearned to express their mutual love. 

At the end of January 1873, between two classes, 
Metchnikoff received a letter from his sister-in-law 
telling him to come in haste if he wished to find his 
wife still living. He delivered his lecture like an auto- 
maton, then went to obtain his leave and hurried off. 
He accomplished the whole journey without a break. 
On arriving at Madeira he found his wife so changed 
that he scarcely knew her, and it was only through 
sheer force of will that he kept his alarm from her. 
She suffered so much that she had to be given morphia 
constantly and could no longer leave her bed. 

Metchnikoff himself was in very poor health ; his 
eyes were so sensitive from overwork that he had 
to remain in the dark, only going into the garden at 
dusk to observe spiders and snails. Time was pro- 
gressing slowly and miserably, and bringing nothing 
but anxiety as to the means to support this sad 
existence. Metchnikoff had hoped to receive the 
Baer prize for a zoological work, but did not obtain 
it : it was refused on the pretext that his memoir 


had been presented in manuscript instead of being 
printed. In reality, the German party had wished 
to give it to a fellow-German. 

A friend -of his, who sent him the bad news, offered 
to lend him 300 roubles, and Metchnikoff accepted ; 
he could now think of nothing but holding out till 
the end. 

One morning the patient's condition suddenly 
became much worse. The doctor was sent for in a 
hurry and declared that it was now a question of a 
few hours. . . . When Metchnikoff went back to his 
wife he found her with eyes wide open and so full of 
mortal anguish and utter despair that he could bear 
it no longer and went out hastily, not to show her 
his dismay. 

This was his last impression ; he never saw her again. 

Only half conscious, he walked up and down the 
drawing-room, opening and closing books without 
seeing them, his mind full of disconnected pictures ; 
he wondered to himself how his family would hear 
the news. Time passed without his realising it. 
Then his sister-in-law came to tell him that all was 
over. This was on the 20th April 1873. 

Metchnikoff's feelings were complex : a mixture 
of crushing despair and of relief at the thought that 
the terrible agony was at last ended. . . . During 
the whole of the sad first night he sat with his sister- 
in-law in a distant room, talking of those things 
which are only mentioned in moments such as these. 
When Dr. Goldschmidt came in the morning to offer 
Metchnikoff his sympathy and help he found him 
apparently almost calm. Metchnikoff asked him to 
make a post-mortem examination of the deceased 
and to look after her sister. A Scottish minister 


came to bring religious comfort and to exhort him 
to look there for consolation. Metchnikoff thanked 
him, but firmly assured him that it was not possible 
to him. 

The funeral took place two days later ; he did not 
attend it and did not see the corpse. Immediately 
after the funeral he left Madeira with his sister-in-law. 
Being no longer anxious to economise, he took with 
him a sick young Russian who wished to see his mother 
again and could not afford the journey. 

After the catastrophe, MetchnikofE felt incapable 
of thinking of the future, his life seemed cut off at one 
blow ; he destroyed his papers and reserved a phial 
of morphia, without any settled intention. They 
journeyed back through Spain ; it was during the 
Carlist insurrection, and several episodes on the way 
distracted their attention. Elie and his sister-in- 
law reached Geneva, where they found Leo Metch- 
nikoff and several relations, among whom he seems 
to have recovered himself. He even related some of 
their travelling experiences, meetings with Carlists, 
frontier incidents, etc., with some spirit. But his 
apparent calm concealed black despair. 

He said to himself : " Why live ? My private 
life is ended ; my eyes are going ; when I am blind 
I can no longer work, then why live ? " Seeing no 
issue to his situation, he absorbed the morphia. He 
did not know that too strong a dose, by provoking 
vomiting, eliminates the poison. Such was the case 
with him. He fell into a sort of torpor, of extra- 
ordinary comfort and absolute rest ; in spite of this 
comatose state he remained conscious and felt no 
fear of death. When he became himself again, it 
was with a feeling of dismay. He said to himself that 


only a grave illness could save him, either by ending 
in death or by awaking the vital instinct in him. 
In order to attain his object, he took a very hot bath 
and then exposed himself to cold. As he was coming 
back by the Rhone bridge, he suddenly saw a cloud 
of winged insects flying around the flame of a lantern. 
They were Phryganidse, but in the distance he took 
them for Ephemeridse, and the sight of them sug- 
gested the following reflection : " How can the theory 
of natural selection be applied to these insects ? They 
do not feed and only live a few hours ; they are there- 
fore not subject to the struggle for existence, they do 
not have time to adapt themselves to surrounding 

His thoughts turned towards Science ; he was 
saved ; the link with life was re-established. 


Anthropological expedition to the Kalmuk steppes Affection of the 
eyes Second expedition to the steppes The eggs of the Geophilus. 

AFTER the misfortune which had befallen him 
Metchnikoff placed his only hope in work, and the 
condition of his eyes was therefore for him a source 
of great preoccupation. He applied to the Peters- 
burg Geographical Society for an anthropological 
mission in order to undertake researches less trying 
to his eyesight than microscopical work. 

As he went deeper into anthropology, he was struck 
by the fact that this science lacked a leading thread 
and was guided by no general idea but reduced to 
mere measurements, very precise and detailed, it is 
true. Metchnikoff wondered whether it would not 
be advisable to apply to anthropology the methods 
used in embryology and to establish an analogy 
between the diverse human races and the different 
ages of the individual. In order to solve this problem 
he had thought at first of visiting the Samoyedes 
as being the most primitive of the aboriginal peoples 
of Russia. But the project was not realisable and he 
determined to visit, at his own expense, the Kalmuks 
of the Astrakhan steppes, also a primitive Mongol race. 

Before his departure he went to see his family 
and that of his late wife. Long afterwards his sister- 
in-law, Mile. Fedorovitch, wrote me the following 
account of that interview : 



He was still suffering from an inflammation of the eyes. 
This man, whom I cannot picture to myself without a micro- 
scope or a book, was, at that sad period of his life, reduced 
to complete inactivity. We had always been struck with 
his power of becoming absorbed in scientific reading, even 
during meals ; it inconvenienced no one, for he heard at 
the same time the conversation that was going on and even 
took part in it from time to time. Now, the day after his 
arrival, I came to call him to tea and found him seated in his 
darkened room with scissors in his hands and the floor around 
him littered with small pieces of paper . . . such was the 
occupation to which he was reduced. 

He told me that, if I liked, he would come to live in Moscow 
and devote his life and his work to OUT family. I refused 
and told him why ; my refusal grieved him, but I was right. 
Besides a feeling of generosity, his offer was actuated by a 
desire for an immediate object in life. Soon after that, he 
started for the Kalmuk steppes in order to undertake anthro- 
pological researches. I was often haunted by the thought of 
his sad figure in the midst of the steppes. 

The journey was difficult and fatiguing. Metch- 
nikoff did not know the Kalmuk language and had to 
depend on interpreters. From the very first he was 
painfully impressed by the brutality of the Russian 
officials towards the natives. At every halt the 
Kalmuks declared that they had no horses ; the 
Cossack who convoyed Metchnikoff would then begin 
to swear and to play with his " nagaika " or leather- 
thonged whip, and the required horses appeared as 
by magic. After a while MetchnikofE became used 
to such scenes and looked upon them as a custom of 
the country. He found it more difficult to put up 
with the indescribable dirt, the smell of mutton fat 
which impregnated the food, and the continual barking 
of dogs during the night, details which destroyed the 
charm and poetry of primitive life. In spite of these 


unfavourable conditions, MetchnikofE worked inde- 
f atigably. The physical measurements of the Kalmuks 
led him to conclude that the development of the 
Mongol race was arrested in comparison with that of 
the Caucasian race ; he found that all the relative 
proportions of the diverse parts of the Kalmuk skeleton 
corresponded with that of youth in the Caucasian 
race : a large head, a long torso, short legs, absolutely 
the relative dimensions of our children. This con- 
clusion was further confirmed by the structure of the 
eyelid in the Kalmuks, of which the fold (epicanthus) 
in the adult corresponds with that of the fold of the 
eyelid in our children. 

These interesting results somewhat raised Metch- 
nikoff's moral, the more so that his eyesight began 
to improve ; he returned to Odessa but found that 
he was still unable to use a microscope. He therefore 
decided to go back to the steppes in order to proceed 
with his researches, and, this time, began his journey 
by the Stavropol province. The steppes there are 
very fine, with tall, luxuriant grasses and a profusion 
of flowers filling the pure atmosphere with perfume ; 
the infinite space and absolute calm offer a peculiar 
and powerful charm. But the population is depressed 
and apathetic, as is the case with that of the Astrakhan 
steppes. The reason must be that the Kalmuks con- 
sume milk which has undergone alcoholic fermen- 
tation, and that provokes a slight but chronic intoxi- 
cation. Yet a few among them are extremely 
intelligent and of fairly high culture. Thus, in the 
course of his ethnographical researches Metchnikoff 
came across a priest (baksha) who imparted to him 
such instructive facts on the principles of the Buddhist 
religion and on the organisation of its clergy that he 


even planned to go with him to Thibet, where no 
stranger can penetrate without the help of an adept. 
This plan, however, was never executed. 

After he had collected numerous anthropological 
data, Metchnikoff went again to the Astrakhan steppes 
in order to verify and to complete his observations 
of the preceding year. Whilst traversing some oases 
where the Russians were making experiments in 
artificial forestry, he had the pleasant surprise of 
finding some Myriapoda (Geophilus) bearing a number 
of eggs. The history of the development of those 
creatures was still unknown a notable lacuna in 
embryology. Delighted at the idea of filling it, 
Metchnikoff did not hesitate to undertake a long and 
difficult extra journey and repaired to Astrakhan, 
taking with him his precious material, in order to 
fetch the necessary apparatus for his researches. 
But during the long journey several eggs perished and 
he had to return to the oasis with a borrowed micro- 
scope to study other eggs on the spot. In spite of 
very difficult conditions and of the persistent weak- 
ness of his eyesight, he succeeded in filling the lacuna 
in the embryology of the Geophilus. 

He had at the same time collected very interesting 
anthropological data. His hypothesis as to the neces- 
sity of applying to anthropology the comparative 
methods of embryology was fully justified, for, thanks 
to that process, he was able to establish a definite 
correlation between the Mongol race and the adoles- 
cence of the Caucasian race. He presented a report 
on the subject to the Anthropological Society of 
Moscow, but, his attention being afterwards turned in 
other directions, he never came back to this subject. 


" As to thee, Hector, thou art to 
me as a father and a revered mother 
and a brother, and thou art my 
husband." The Iliad. 

Studies on childhood The family in the upper flat Lessons in zoology 
Second marriage Private life Visit and death of Lvovna 
Nevahovna Conjugal affection. 

METCHNIKOFF'S anthropological researches led him 
to the study of childhood, which in its turn suggested 
reflections on questions of Pedagogy. His eyesight 
was still weak and his hunger for activity very great ; 
in order to satisfy it, he gave lessons in a Lycee and 
public lectures in the Odessa University. Though 
time was passing, Metchnikoff could not get used to 
his solitude ; he spent his active kindness on his 
friends and all around him, whilst living like an 
ascetic and giving away all that he could spare. But 
nothing could quench his thirst for a family life and 
affectionate intimacy. 

My family at that time lived in the same house 
as he did, on the floor above him ; we were eight 
children, our ages ranging from one to sixteen years. 
We were noisy neighbours and we incommoded Metch- 
nikoff, who was awakened every morning by the 
noise in our kitchen, where meat was being minced 
for the children. One fine day he could stand it no 
longer and went upstairs to ask if this nuisance could 
not be stopped ; my father promised that he would 


see that it ceased. We were all seated round the tea- 
table when he came in, and, seeing a stranger, my 
sister and I hurriedly collected our lesson books, and 
hastened to leave the room. We did not even have 
time to distinguish Metchnikoff's features, but were 
struck by his paleness. Shortly after that incident 
we met him at the house of a mutual friend. He had 
already seen us from his window as we went off to 
the Lycee, and it used to amuse him to see us bravely 
stepping over a large pool of water which was per- 
manent in the street. 

One of his pupils was a professor in our Lycee, 
and Elie had the opportunity of informing himself 
concerning our studies. Having heard that I was 
interested in natural science, it occurred to him to 
offer to give me lessons in zoology. I was delighted. 
He asked and obtained permission from my parents, 
and we eagerly set to work. Elie, being strongly 
attracted by me, returned to his former idea of 
training a girl according to his own ideas and after- 
wards making her his wife. He might have realised 
his programme of completing my education first and 
marrying me afterwards if he had not been prevented 
by the complete lack of accord between his ideas and 
those of my father. It was the eternal conflict of 
two generations, "fathers and children." My father 
was an excellent man, of great nobility of character, 
but he was a type of the old Russian patrician school 
and belonged to a different epoch, with different 
opinions and customs. This caused inevitable and 
frequent disagreements, and Elie decided to ask for 
my hand without further delay. 

My mother was much younger than my father, 
and her sympathies were all with the young genera- 


tion. She was an idealist, gentle, intelligent and 
artistic, and, in her youth, had painted and played the 
violoncello, but a very early marriage and numerous 
children had forced her to give up the practice of art, 
to her lifelong regret. Great sympathy arose between 
her and Elie ; she supported him in everything and 
became for him a tenderly attached friend. He 
explained to her his theories on marriage, and then 
confided to her his feelings towards me. My extreme 
youth troubled her very much, but Elie endeavoured 
to reassure her, saying that he fully understood the 
rashness of his projects, but that he was ready to 
suffer all the consequences ; in fact, he declared, if 
he did not succeed in making me happy, he would 
have the strength to help me to create another exist- 
ence for myself. I had not suspected my Professor's 
feelings towards me, and was deeply moved when I 
was told of them ; it seemed to me impossible to 
understand that this superior, this learned man could 
wish to marry a little girl like myself ! I thought 
with terror that he must be mistaken about me ; I 
felt as if I were going up for an examination without 
any previous study. However, I had a great affec- 
tion and admiration for Elie ; I was attracted by his 
whole personality, which produced a strong impression 
upon others as well as upon myself. This is how 
Setchenoff describes him, in his own autobiography : 

Elie Metchnikoff was the soul of our circle. Of all the 
young men I have known in my life, young Metchnikoff was 
the most attractive with his lively intelligence, inexhaustible 
wit and abundant knowledge of all things. He was, in Science, 
as serious and as productive (he had already done much in 
zoology and acquired a great name in that branch) as he was 
full of life and varied interest in a circle of friends. 


Moreover, my young imagination was impressed 
by his sad history and by his interesting appearance, 
at that time not unlike a figure of Christ ; his pale 
face was illumined by the light in his kindly eyes, which 
at times looked absolutely inspired. My whole heart 
went out to him, but I was not yet ripe for matrimony 
and was somewhat thrown off my balance by the 
unexpectedness of the event. Fearing that I was not 
up to his level, I used to try beforehand to find 
worthy subjects of conversation in order that he should 
not feel bored in my society, but everything I thought 
of seemed to me so clumsy and stupid that I rejected 
one subject after another until he came and found me 
at a loss. He could not understand how deeply I 
was troubled, and cannot have been satisfied with my 
attitude, which really was that of a zealous pupil. 

Our marriage took place in February 1875 ; it 
was a very cold winter and the ground was covered 
with a thick coating of glistening snow. A few hours 
before the ceremony my brothers came with a little 
hand sledge to fetch me for a last ride. " Come quick," 
they said, " this evening you will be a grown-up lady, 
and you can't play with us any more ! " I agreed, 
and we rushed out to the snowy carpet which covered 
the great yard of our house. In the midst of our 
mad race my mother appeared at the window ; she 
had been looking for me everywhere and was much 
disturbed. " My dear child ! what are you thinking 
of ? It is late, you have hardly time to dress and 
to do your hair ! " " One more turn, mother ! It is 
the last time, think of it ! " Other childish emotions 
awaited me ; my wedding-dress was the first long 
dress I had ever worn, and I feared to stumble as I 
walked. Then, too, I was frightened at the idea of 


entering the church under the eyes of all the guests. 
My little brother tried to reassure me by offering to 
hold my hand, and my mother made me drink some 
chocolate to give me courage. 

Elie was awaiting us at the entrance ; my shyness 
increased when I heard people whispering around us, 
" Why, she is a mere child ! " The ceremony took 
place in the evening, after which Elie wrapped me 
carefully in a long warm cloak and we set off, the 
sledge gliding like the wind, towards our new home. 
In spite of the day's emotions, I rose very early the 
next morning in order to work at my zoology exercises 
and to give my husband a pleasant surprise. He was 
now free to superintend my education, a very difficult 
and delicate task when having to do with a mind as 
unprepared for life as mine was. 

The scientific methods which Metchnikoff applied 
to everything might have constituted a grave error 
at this delicate psychological moment ; yet, in many 
ways, he showed himself a strangely clear-sighted 
educator. He made it a principle to give me entire 
liberty whilst directing me through the logic of his 
arguments. It is with deep gratitude that I realise 
how he, so superior to me, took care not to stifle my 
fragile individuality but to respect it and to encourage 
it to develop. Like all Russian young people of the 
time, I was very enthusiastic concerning political and 
social questions that I was not mature enough to 
understand, and my father forbade us to frequent 
political circles with which he had no sympathy, fear- 
ing that we might be influenced by them. Elie, on 
the contrary, left me full liberty, though he himself 
disapproved of my tendencies. He considered that 
political and social questions belonged to the realm of 


practical experience, in which young people were 
lacking, as also in practical preparation. He never 
prevented me from making myself acquainted with 
the social movement, but submitted it to close analysis 
and criticism ; it is owing to this very efficacious 
method that I did not become one of the numerous 
political victims of that time. 

Elie took a lively and warm interest in everything 
which concerned me. Not having had time to pass 
my final examinations from the Lycee before my mar- 
riage, I was now obliged to go up before a special 
board for the whole curriculum. He helped me to 
prepare this, even the catechism, with the utmost 
keenness and gaiety, enlivening the driest subjects 
by means of interesting and instructive reading. I 
was glad to continue my biological studies under his 
direction after I had passed my examinations. Not 
only did he give a general interest, a leading thread, 
to every particular subject, but he also knew how to 
develop independent work. For instance, he made 
me compare representative examples of divers groups 
by practical study in order to let me deduce for 
myself their characteristics and their generic con- 

And it was not my education only which interested 
him ; he associated me with every detail of his life 
and initiated me into his thoughts and his work ; 
we read together a great deal, he had an excellent 
delivery and liked reading aloud. 

He thoroughly enjoyed giving me pleasure ; we 
often went to concerts and theatres, and beautiful 
music or dramatic scenes moved him even to tears. 
Musical themes haunted him, and he would whistle 
them softly to himself even at his work. Without 


caring for luxury, he was glad to contribute to the 
simple embellishment of our home because he knew 
I appreciated it. When we travelled, always with 
scientific research as an object, he never failed to 
point out every interesting feature that we happened 
to pass. He had a peculiar talent for making a 
journey instructive as well as attractive ; his eager- 
ness, infectious gaiety, inquisitive mind, and remark- 
able organising faculty made of him an incomparable 
guide and companion. 

We worked together for many years ; it was both 
delightful and profitable to work with him, for he 
opened out his ideas unreservedly and made one 
share his enthusiasm and his interest in investigations ; 
he could create an atmosphere of intimate union in 
the search for truth which allowed the humblest 
worker to feel himself a collaborator in an exalted 

Though I always took a strong interest in scientific 
questions, Art was the real passion of my life. But, 
imbued as I was with the narrow, utilitarian views 
which surrounded my youth, I had looked upon Art 
as a luxury which should not be indulged in at a time 
when the poorer classes could not read and write. 
When at last I became emancipated from this fallacy, 
my husband did his best to encourage my artistic 
development though he himself did not appreciate 
plastic art. Form and colour in themselves or in 
harmony did not appeal to him ; he took much more 
interest in a subject than in the way it was treated ; 
he liked psychological or realistic work, landscapes, 
" genre " pictures, but classical, Kenaissance, or Im- 
pressionist works bored him. In spite of the diver- 
gence of our tastes in that connection, he never ceased 


to encourage me or to take an active interest in my 
work ; often and often he accompanied me to picture 
galleries, making sincere and somewhat pathetic efforts 
to appreciate the beauty of great masterpieces. 

Next to music he enjoyed Nature most, perhaps 
because it offered him an inexhaustible source of 
scientific observation. His wearied nerves caused him 
to seek for soothing impressions, and calm, quiet 
ponds were what he preferred, with their reeds and 
aquatic plants, among which he loved to discover tiny 
beings, hidden under the leaves and below the surface 
of the water. 

Teaching and public work took up nearly the whole 
of his time ; his leisure was devoted to home life 
and to an intimate circle of friends with whom he 
was bound by a common scientific fervour and by a 
University life. He kept up those friendships even 
after life had scattered them. His active kindness 
made him a centre of attraction to his relations and 
we were always very much surrounded. After his 
father died, in 1878, his mother and two of her grand- 
children came to live with us. She was at that time 
sixty-four years of age and had the appearance of an 
old lady ; she did not follow the fashion but wore her 
white hair simply parted and framing her face ; alone 
her fine dark eyes had preserved their youthful 
sparkle and bore witness to her former beauty. She 
had a bright and cheerful disposition and a charming 
kindliness to every one ; her desire for activity was 
unfortunately thwarted by the state of her health. 

Elie showed his mother a tender solicitude which 
manifested itself in the smallest details ; for instance, 
he who detested cards would play Patience with her ; 
or he would drive her round the markets, which 


interested her like the good housekeeper she was. 
When he came in from the laboratory he never failed 
to go to her to ask her for details of her health ; he 
talked to her playfully and affectionately, making 
her laugh, telling her the incidents of the day. She 
continued to be interested in everything, especially 
that which concerned her dear Elie, the " consolation 
of her life," as she called him. 

In spite of his affection for his mother, he bore 
her almost sudden death very stoically, knowing as 
he did that the grave heart disease from which she 
suffered was bound to cause her increasing pain. 

My family became his, and the relations between 
him and my father became such that the latter, 
feeling ill and nearing his end, made him our guardian. 
Until the last my mother preserved for my husband 
a tender friendship which he fully returned. For 
years he bore the burden and responsibilities of the 
family. With my young brothers and sisters he kept 
up a tone of merry affection ; always indulgent with 
them, he was anxious to neglect nothing that could 
be useful. Though ever led by the desire to procure 
happiness around him, it sometimes happened that 
he made a mistake in his appreciation and failed to 
reach his goal. The human soul is a riddle, life is 
complicated, and we ought not always to judge by 
results but by motives. ... As far as I am personally 
concerned, his affection, kindness, and solicitude have 
always been unbounded. If during early years a few 
misunderstandings arose between us, they were due 
to my youthful obstinacy or to his nervous sensitive- 
ness. We had our trials, but our friendship and deep 
affection emerged from them stronger and purer than 
ever. At a certain time, Elie, believing that happiness 


called me elsewhere, offered me my liberty, urging 
that I had a moral right to it. The nobility of his 
attitude was the best safeguard. ... As years went 
on, our lives became more and more united ; we lived 
in deep communion of souls, for we had reached that 
stage of mutual comprehension when darkness flees 
and all is light. 


Metchnikoff at the age of thirty Lecturing in Odessa University, from 
1873 to 1882 Internal difficulties Assassination of the Tsar, 
Alexander II. Further troubles in the University Resignation 
Bad health : cardiac symptoms Relapsing fever Choroiditis 
Studies on Ephemeridse Further studies on intracellular 
digestion The Parenchymella Holidays in the country Experi- 
ments on agricultural pests. 

ELIE METCHNIKOFF was now thirty years old, and his 
personality was fully characterised though it had not 
yet reached the culminating point of its development. 

His dominating point was his passionate vocation ; 
his worship of Science and of Reason made of him 
an inspired apostle. He had the faults and qualities 
of a rich and powerful nature. Vibrating through all 
the fibres of his being, he shed life and light around 
him. His temper was violent and passionate ; he 
could bear no attack on the ideas which were dear 
to him, and became combative as soon as he thought 
them threatened. His was a wrestler's temperament ; 
obstacles exasperated his energy and he went straight 
for them, pursuing his object with an invincible 
tenacity ; he never gave up a problem, however 
difficult, and never hesitated to face any sacrifice or 
any privation if he thought them necessary. 

A strange contradiction with this iron will was 
offered by occasional disconcerting impulses, like that 
which caused the failure of his first journey abroad, 
or by sudden attacks of fury for insignificant reasons 


such as an unexpected noise in the street, a cat mewing 
or a dog barking, or angry impatience when he could 
not solve a frivolous puzzle, etc. This impulsive 
disposition gradually calmed down as he grew older, 
and ultimately very nearly disappeared. 

In his personal relations also he was apt to lose 
his temper, but a reaction very soon followed the 
outburst, and his efforts to be forgiven when he felt 
guilty were very touching. On the other hand, he 
did not easily forget an offence, though no desire for 
revenge ever soiled his soul, and his gratitude for 
kindness was absolutely indestructible. 

He harboured pessimistic theories to that extent 
that he looked upon the procreation of other lives as 
a crime on the part of a conscious being ; his physical 
and moral sensitiveness was intense. And yet he 
had inherited from his mother a natural gaiety and 
delightful elasticity which always ended by gaining 
the upper hand. He was fond of joking ; his wit was 
occasionally somewhat cutting, but that was entirely 
due to the appropriateness of his remarks ; he never 
hurt people's feelings intentionally. He sometimes 
gave offence by a professional habit of using personal 
and concrete instances by way of arguments, but he 
applied the process to himself as well ; it was the 
objective method, nothing more, and those who knew 
him well never doubted it. 

His benevolence was most active and never insipid, 
though marked by an almost feminine sensibility. 
He was an incomparable companion and friend, and 
had the gift of smoothing difficulties and inspiring 
courage, security, and confidence. He took the 
greatest interest in others and easily came down to 
their level, always finding points in common, " an 



opportunity for the study of human documents," he 
said. Thus he conversed simply and sympathetically 
with the humble as with the great, with the young as 
with the old. It was no mere intellectual interest that 
he bore them, but he put his whole heart into it, which 
made him extremely easy to approach. And yet he 
never departed from absolute freedom of speech, some- 
times mixed with harshness. Truth and sincerity, for 
him, came above everything ; he carried the courage 
of his opinions to the highest degree, even if it was 
likely to shock his hearers or to do him harm. He 
jealously guarded his independence and nothing could 
force him to act against his convictions. Full of 
enthusiasm, always interesting, he enlivened all 
around him. His ideas and his activity were in 
constant effervescence ; no serious question left him 
indifferent ; he read everything, knew about almost 
everything, and willingly informed others ; his vibrat- 
ing expansiveness made him a centre of attraction in 
his private life as in the laboratory or in any other 
sphere of activity. 

From 1873 to 1882 his energies were chiefly 
absorbed by teaching and by the inner life of the 
University of Odessa, into which he threw himself 
with his usual enthusiasm. His lectures were full of 
life, always bringing out general ideas to throw light 
upon the most arid facts ; he made use of these as 
an architect utilises coarse materials in order to erect 
a harmonious edifice. His creative power endowed 
his lectures with an aesthetic character in spite of 
their extreme simplicity ; not that he concerned 
himself much about form, but because of his wealth 
of ideas and the logical way in which he developed 
them, starting from the simple and reaching the 


complex in a harmonious synthesis. His own enthusi- 
asm established a living bond between him and his 

He was on excellent terms with the students, 
though he made no bid for popularity. Not only did 
he give no encouragement to the prevailing tendency 
of the young men towards politics, but he endeavoured 
on the contrary to bring them back to their studies ; 
he tried to prove to them that social problems demand 
knowledge and a serious practical preparation. Other- 
wise, said he, social life would be as medicine was 
before it entered into the path of science, and when 
any middle-aged woman, any bone-setter, was allowed 
to practise therapeutics. At the same time, students 
found in him willing protection in the persecutions 
directed against them, and earnest help in their work 
when they showed the least interest in it ; he would 
eagerly welcome the smallest spark of the " sacred fire." 

Owing to the absolute independence of his ideas 
and conduct he had great influence on young men, 
and this caused him to be looked upon in adminis- 
trative spheres as a " Red " almost an agitator. In 
reality he was struggling against the inertia and 
reactionary forces which were shackling the normal 
development of culture and science in Russia. He 
called himself a " progressive evolutionist," for he 
considered that alone a deep and conscious evolution 
could give stable results and lead to real progress. 
He thought that Revolution, and especially Terrorism, 
merely provoked a reaction which might be long- 
lived, and that, as long as the people were not suffi- 
ciently educated, a revolution might easily result in 
the transfer of despotism from one party to another. 
Socialistic doctrines did not satisfy him ; according 


to him, they did not leave sufficient scope to personal 
initiative and to the development of individuality, 
two factors which he considered as essential to every 

He looked upon scientific work as his mission, and 
avoided politics because he did not think himself 
competent to deal with them. But scientific activity 
being closely limited by the state of the University, 
which was badly oppressed at that time by re- 
actionary powers, he was led to take part in the 
defence of the University's right to autonomy. He 
brought all his energies into the struggle, though 
trying to keep from party tactics and to act purely 
in the interests of science. For instance, he would 
vote either for a Eadical or a Conservative without 
sharing the opinions of either, but merely guided by 
their scientific value. 

At the beginning of his scientific career at Odessa 
he led a very active campaign in favour of the teaching 
of Natural Science. He urged that, in order to teach 
properly, Natural History professors should them- 
selves have made independent researches on living 
fauna and flora, and tried to introduce a series of 
measures to allow biologists special holidays and 
missions to desirable places, at the proper seasons, for 
research purposes. " There is no doubt," he said, 
" that scientific activity would be much increased if 
the proposed measures were adopted. Then, before 
long, our young scientists would not need to go to 
study in German universities, but could go abroad 
already prepared to undertake independent research." 
The Commission which examined his report demanded 
certain modifications, " because of the Imperial in- 
junction to be very strict in granting travelling 


permits to professors. ' ' Metchnikoff somewhat altered 
the text, which, after being adopted by the University 
Council, was rejected by the Ministry and remained 
without effect. Thus was every independent sugges- 
tion stifled, even when it had but a purely scientific 

Soon the situation of the Odessa University became 
even more difficult. Between 1875 and 1880 reaction 
increased considerably, and the inner life of the 
University became very unfavourable to any scientific 
activity. Already before that it was teeming with 
intrigues, the Professors of Ukrainian origin being 
hostile to the " Muscovites." Yet it was still pos- 
sible to remain apart from these local intrigues, until 
political reaction, filtering into the University, created 
in it the deepest divisions. The hostility of parties 
was now based on political opinions, either " Reac- 
tionary " or " Liberal." The students were being 
more and more carried away by this movement and 
no longer took any interest in their studies. 

All these conditions made normal teaching and 
scientific work impossible, and Metchnikoff, seeing that 
politics from above and from below now swallowed 
up everything, tried to take refuge in his laboratory, 
but in vain ; even there he could no longer find the 
necessary calm, and only during the holidays could 
he really work. 

Thus passed the years until March 1, 1881, when 
the crime which ended the days of Alexander II. 
was followed by a great reactionary movement. The 
authorities, seeing conspiracies and plots everywhere, 
persecuted without cause all the elements which were 
ticketed as " dangerous." Though the University 
still preserved its autonomy, this was entirely fictitious, 


for the Ministry thwarted every desire for indepen- 
dence ; the nomination of professors elected by the 
University Council was only ratified by the Ministry 
if they were reactionaries, without any regard for 
their scientific value. Soon the Chairs were occupied 
by ignorant men of doubtful morality. 

The life and honour of the University became 
endangered, and Metchnikofi found himself obliged 
to take part in the struggle ; he did so with vehem- 
ence and energy ; the independence of the University 
was involved, and, as long as he could hope to save it, 
he struggled. At the meetings of the Council and 
of the Faculty he never failed to give vent to his 
critical opinions with a vehement frankness which 
earned him in the University the reputation of an 
" enfant terrible" In the meanwhile every resolution 
passed by the Council, if not reactionary in character, 
was systematically quashed by the Ministry, which 
thus paralysed every means of action, and Metchni- 
koff found himself faced with the alternative of sub- 
mitting or handing in his resignation. He decided for 
the latter: his convictions were involved, and more- 
over his health could not withstand the continual 
agitation and strain on his nerves. 

As we could not afford to live in independence, he 
applied for a vacant post of entomologist in the 
zemstvo 1 of Poltava, and at the same time wrote out 
his resignation, holding it in readiness for an oppor- 
tunity which was not long in coming. 

The Conservative party in the Faculty arose against 
a Liberal professor who had accepted a very clever 
thesis in which the Reactionaries perceived Socialist 
tendencies. The Dean of the Faculty proposed that 

1 Rural administration. 


all such theses should be refused, and the Faculty 
approved. This was the signal for a storm in the 
University, the Dean was hooted by the students, and 
many of them were threatened with being expelled. 
The Curator desired the more influential professors, 
of whom Metchnikoff was one, to intervene with the 
students in order to bring disorder to an end, and the 
professors consented, on condition that the offending 
Dean should resign. The Curator promised that 
he should be asked to do so, and order was imme- 
diately restored ; but the Dean remained and many 
students were severely and unjustly punished. Metch- 
nikoff thereupon produced his resignation, which was 
promptly accepted, and thus his University career 
came to an end. 

Besides his University lectures, he gave public 
lectures on Natural History which were attended by 
a number of female students, for women at that time 
were only admitted to the Faculty of Medicine, and 
these lectures were extremely useful to them. Metch- 
nikoff, though he did not believe that women could 
accomplish creative work in science, was strongly 
in favour of higher education for women, considering 
it as necessary to their general intellectual develop- 
ment. Genius, he thought, was peculiar to the male 
sex, no woman having created anything " of genius " 
even in domains which had always been accessible to 
them, such as music, literature, and the applied arts. 
The very rare exceptions, to his mind, only proved 
the rule ; yet he did not draw the conclusion that 
woman was in any sense inferior to man. He merely 
held that her gifts are different from those of men. 

Metchnikofl's health had been seriously shaken 


by the emotions and annoyances of university life. 
Already in 1877, after political intrigues at the 
University, he had felt the first symptoms of cardiac 
trouble, which were the beginning of a long period of 
ill-health. He consulted Bamberger, a great Viennese 
physician, who, however, found nothing serious, and 
merely forbade him the use of wine and tobacco, 
to neither of which was he addicted. 

His health suffered further through the violent 
anxiety which he went through in 1880 whilst I lay 
dangerously ill with typhoid fever, contracted in 
Naples. Though worn out with devoted nursing, he 
tried to make up the time lost to research and over- 
worked himself, with the result that cardiac trouble 
was followed by fits of giddiness and unconquerable 
insomnia. He fell into such a state of neurasthenia 
that, in 1881, he resolved in a moment of depression 
to do away with his life. 

In order to spare his family the sorrow of an obvious 
suicide, he inoculated himself with relapsing fever, 
choosing this disease in order to ascertain at the same 
time whether it could be inoculated through the 
blood. The answer was in the affirmative : he became 
very seriously ill. His condition was aggravated by 
anxiety concerning the University ; for he was suffi- 
ciently conscious to be aware of the events which were 
taking place in Russia. The murder of Alexander II. 
caused him to foresee a political reaction of the most 
terrible type ; already, a reactionary Rector had been 
appointed. Metchnikoff developed intense jaundice 
and had a serious relapse with alarming cardiac weak- 
ness; during the crisis he had a very distinct prevision 
of approaching death. This semi-conscious state 
was accompanied by a feeling of great happiness ; 


he imagined that he had solved all human ethical 
questions. Much later, this fact led him to suppose 
that death could actually be attended by agreeable 

His robust nature, however, triumphed over all 
these grave complications, and, during his convales- 
cence, he was rilled with a joy of living such as he 
had never experienced before ; from that moment his 
moral and physical balance was completely restored. 
There was one unpleasant sequel to his illness, an 
acute affection of the sight (choroiditis), but it for- 
tunately disappeared without leaving any traces, and, 
in fact, he never suffered again from his eyes, in spite 
of his constant use of the microscope. 

After his recovery he had a renascence of vital 
intensity ; the life instinct developed in him in a high 
degree ; his health became flourishing, his energy and 
power for work greater than ever, and the pessim- 
ism of his youth began to pale before the optimistic 
dawn of his maturity. However, the relapsing fever 
had very probably increased, if not started, the cardiac 
trouble which eventually caused his death. 

During the time when Metchnikoff was forbidden 
the use of the microscope on account of his eye weak- 
ness, he studied Ephemeridse from the point of view of 
natural selection. He wished to elucidate the manner 
in which this selection operates during the very short 
life of those insects : the rudimentary structure of 
their buccal organs does not allow them to feed 
themselves, and they have no time to adapt them- 
selves to external conditions. 

During the 1875 holidays, at Gmunden and on the 
Danube, he observed the nuptial flight of the may- 
flies, a phenomenon which constitutes their short 


adult existence, preceded by a long period in the 
larval state. Thousands of these diaphanous, ephe- 
meral insects swarm above the water in a compact 
cloud ; now and then, dead Ephemeridae fall like 
snow-flakes, and that is the final and tragic completion 
of the nuptial flight. MetchnikofE wished to unveil the 
mechanism of this sudden death, evidently due to 
a physiological cause ; but he obtained no definite 
results either that year or the following, when he 
continued his observations in the Caucasus. He 
realised that the life of these insects was too short to 
allow him to solve the problems which interested him, 
and, his eyes now being cured, he went back to his 
studies on the origin of multicellular beings or metazoa. 

He studied the development of inferior sponges 
and ascertained that they possess the three embry- 
onic layers which correspond to those of other animal 
types, but that these layers have not the same degree 
of independence or differentiation. He found that 
in certain inferior sponges the mesoderm develops 
before the endoderm and gives birth to it. These two 
layers, born one from the other, manifest common 
primordial characters. Therefore he was in no wise 
surprised to discover that, in these inferior sponges, 
the amoeboid and mobile cells of the mesoderm fulfil 
digestive functions equally with, and even more than 
those of the endoderm; in fact, with primitive beings, 
functional characters are not more strictly delimit- 
ated than morphological characters. It is only a 
more advanced differentiation which separates them. 

He connected these new facts with that which he 
had observed in 1865 in one of the lower worms, the 
earth planarian Geodesmus bilineatus. This worm is 
actually without a digestive cavity, for the latter is 


entirely filled by parenchymatous cells inside which 
digestion takes place. 

By their primitive structure, lower sponges and 
worms come near the higher Infusoria, to which they 
are even more closely related by this intercellular 
digestion which is common to them. 

This led Metchnikoff to ask himself whether this 
was not, generally speaking, the primitive mode of 
digestion. He carried out numerous researches on 
this point during the following years, and found the 
same intercellular digestion in other lower worms, 
such as the Mesostoma and aquatic planarians, and 
afterwards in some lower Coelentera and some Echino- 
derma. He was thus enabled to establish definitely 
that the primitive mode of digestion was really inter- 
cellular, for the lower multicellular animals either do 
not possess any digestive cavity or else their digestive 
cavity develops late, as for instance with lower jelly- 
fish or with hydropolypi. Even when the cavity is 
developed in these inferior animals, the digestive 
functions are fulfilled by the mesodermic cells. 

The question as to what are the ancestral forms of 
multicellular animals cannot be solved through direct 
observation, for there is a lacuna between them and 
unicellular beings, a lacuna which is due to the dis- 
appearance of intermediary forms. It can only be 
filled by hypotheses, based upon the embryology of 
those animals which, in their embryonic development, 
repeat the inferior forms from which they are derived, 
thus reflecting the general evolution of living beings. 
It was therefore to the embryology of lower multi- 
cellular beings that Metchnikoff turned, in order to 
endeavour to reconstitute their origin and to show the 
link between them and unicellular beings. 


We know that the ovule or primitive genital cell 
of every animal may be compared to a unicellular 
organism. After fertilisation the egg undergoes con- 
secutive divisions or segmentation ; each segment 
constitutes a new cell, and their aggregation forms a 
hollow sphere called a blastula, which is similar to a 
colony of unicellular beings. The blastula differenti- 
ates itself into embryonic layers, the ectoderm, endo- 
derm, and mesoderm already mentioned. 

In the majority of animals the origin of the first 
two layers, ectoderm and endoderm, is due to the 
invagination of one of the poles of the blastula ; the 
invaginated part of the walls forms the internal layer, 
the endoderm, and lines the cavity produced by 
invagination ; this cavity thus becomes a digestive 
cavity. This stage of development, called gastrula, 
is similar to a cup with a double wall, of which 
the outer is the ectoderm and the inner the endo- 

This stage, discovered by Kovalevsky, is to be 
found in the evolution of most animals and corre- 
sponds to the adult stage of some of them. It was 
consequently considered as the primitive type of multi- 
cellular beings. 

Haeckel founded thereupon his theory of the 
gastrcea, according to which the common ancestor 
of animals was a lower animal, now disappeared, 
and similar to that stage of development. He 
therefore gave to this hypothetical animal the name 
of gastrcea. 

Metchnikoff, however, discovered among primitive 
multicellular animals, such as sponges, hydroids, and 
lower medusae, a stage of development still more 
simple than the gastrula ; this stage is without a 


digestive cavity and only assumes the gastrula form 
in its ulterior evolution. He also made the remark- 
able discovery that, in the most primitive multi- 
cellular animals, the endoderm is formed, not by means 
of invagination, but by the migration of a number of 
flagellated cells from one pole of the wall of the 
blastula into the central cavity. These cells draw in 
their flagellum, become amoeboid and mobile, multiply 
by division, fill the cavity of the blastula, and become 
capable of digesting. They originate the digestive 
cells of the complete organism and give birth to the 
mesoderm, which explains how the latter comes to 
contain a number of devouring cells even though 
these do not constitute digestive organs properly 
so called. Metchnikoff gave to that stage the name 
of 'parenchymella, for the migrating cells constitute 
the endoderm in the condition of a parenchyma. 

The invariable presence of this stage in the simplest 
multicellular animals, the primitive amoeboid state 
of the endodermic cells, cases of ulterior transforma- 
tion of the parenchymella into the gastrula form in 
certain animals, the absence of a differentiated 
digestive cavity, all that proved, according to 
Metchnikoff , that the parenchymella is more primitive 
than the gastrula, and is therefore entitled to be con- 
sidered the prototype of multicellular beings. 

He saw a confirmation of this in the fact that 
primitive adult animals also have no digestive cavity 
but merely an intracellular digestion (sponges, tur- 

He concluded that the common ancestor of 
multicellular beings was a being constituted by an 
agglomeration of cells without a digestive cavity, but 
endowed with intracellular digestion, like that of the 


" parenchymula " stage of development. He therefore 
gave to that hypothetical ancestor the name of 

Later, in 1886, he definitely formulated his theory 
of the genesis of multicellular beings, and having 
already stated the phagocyte theory, he substituted 
for the name parenchymella that of phagocytella, which 
indicated at the same time the primitive mode of 
digestion of that hypothetical ancestor. 

Reduced to its simplest form, it presented, accord- 
ing to Metchnikoff, a certain analogy with a colony 
composed of unicellular beings of two kinds : the 
first, flagellated, forming the external layer, and the 
others, amoeboid, occupying the centre of the colony 
and capable of digesting. 

It may be interesting to mention here that, in this 
hypothetical description, Metchnikoff foresaw the 
existence of similar, but real, beings discovered a year 
later by Saville Kent, namely, the flagellated colonies 
of Protospongia. 

Thus the link between the unicellular and the 
multicellular beings could be constituted through the 
intermediary of flagellated colonies on the one hand 
and, on the other hand, of beings similar to a phago- 
cytella. The indivisible colony became the muUi- 
cellular individual. 

While studying the genealogy of beings, Metch- 
nikoff continued his researches on intracellular diges- 
tion. In 1879, at Naples and at Messina, he was 
able to establish the fact that the mesodermic cells 
of many larvae of Echinodermata and Ccelenterata, 
endowed with a digestive tube, nevertheless contained 
strange bodies. Therefore, even complicated organ- 
isms with a differentiated digestive system could still 


contain at the same time some primitive cells with 
an autonomous digestion. 

All these researches on the unity of the origin of 
multicellular beings and their morphological elements, 
and also those concerning intracellular digestion, were 
gradually preparing Metchnikofl's mind for the con- 
ception of the phagocyte theory. 

We spent the summer of 1880 with my family in 
the country. The cereals were invaded by a harmful 
beetle, the Anisoplia austriaca, which was devastat- 
ing the country. MetchnikofE took the study of this 
scourge to heart and tried to find a remedy. He 
had, the preceding year, observed a dead fly enveloped 
with a sort of fungus which had evidently been the 
cause of its death. Hence he conceived the idea that 
it might be possible to combat harmful insects by 
provoking epidemics among them. He now returned 
to this idea ; on dead bodies of Anisoplia he found 
a small fungus, the muscardine, which was invading 
the insects by means of filaments, and he succeeded 
in infecting healthy beetles. 

At first he confined himself to laboratory experi- 
ments ; then a great landowner, Count Bobrinsky, 
placed experimental fields at his disposal. As the 
acquired results were very encouraging, Metchnikofi, 
forced to leave the neighbourhood, left a young 
entomologist in charge of the application of his 
method. So far as he himself was concerned, this 
study proved the starting-point of his researches on 
infectious diseases. 


Death of his father- and mother-in-law Management of country estates 
Agitation and difficulties Departure for Messina with young 
brothers- and sisters-in-law. 

IN the spring of 1881, Metchnikoff having recovered 
from relapsing fever, we went to stay with my parents 
at KiefE and found my father dying. He entrusted 
Elie with the care of the family, and they came to 
live with us at Odessa. But, the following year, we 
had the misfortune to lose my mother also. From 
that moment my husband took upon himself the 
responsibility of the whole family. 

Our resources came from landed property, and he, 
who had never concerned himself with rural questions, 
had to make himself acquainted with them. In this 
he was greatly helped by a neighbour, Count Bobrinsky, 
through whose influence he came to abandon the purely 
theoretical opinions he had hitherto held concerning 
agrarian questions. He had considered communal pro- 
perty as a desirable agrarian system : Count Bobrinsky 
showed him that it was not so, at any rate in Little 

Metchnikoff came to the country with the keenest 
desire to make himself useful. First of all he devoted 
the gratuity which he had received on leaving the 
University, to a school which my sister and myself 
desired to open in our family property. But we were 


met by administrative opposition which nearly 
wrecked our plan, under the pretext that it was 
intended for political propaganda. And though 
cordial relations were established from the first 
between Metchnikofi and the peasantry, many com- 
plications were unavoidable, due to the general 
agrarian situation, to the insufficiency of the peasants' 
allotments, and to their primitive methods of culti- 

My father, whose property was in the province of 
Kiefi, had inherited another domain in that of 
Kherson ; Metchnikofi therefore had to manage both 
estates and to adapt himself to their very different 
respective circumstances. The majority of the farmers 
in Little Kussia at that time were Jews and were 
beginning to be persecuted both by the Government 
and by the peasants ; Elie was constantly obliged to 
intervene. In the province of Kherson, it was a 
tradition with the peasants that the land should 
belong to them, and they imagined that this could 
be brought about by the simple elimination of the 
farmers. Therefore they inflicted constant vexations 
upon the latter, allowing cattle to pasture in their 
crops, pulling up their beetroots, etc. Metchnikofi 
attempted in vain to re-establish peace by means of 
compromise ; he persuaded a farmer to sub-let part 
of the land to the peasants, but this had to be given 
up, for the latter did not carry out their engagements. 
Relations between the farmers and the peasants were 
getting worse and worse, and Metchnikofi, foreseeing 
a catastrophe, warned the local administration that 
the situation was getting very grave and would lead 
to irreparable consequences. He was merely told that 
preventive measures would be useless ; hereupon the 



peasants brutally murdered a keeper who was turning 
the cattle away from the crops. Then at last the 
administration awoke, arrested the murderers, and 
twelve men were exiled to Siberia. 

All this caused Metchnikoff the deepest anxiety, 
the more so that he was absolutely incapable of 
altering the situation. As soon as it became possible, 
he sold to the peasants that portion of the land which 
belonged to us personally ; until then, the property 
had been common to the whole family, of which the 
younger members were not yet of age. This, however, 
was not a general solution, and these moral pre- 
occupations, as well as the heavy responsibility in- 
cumbent upon him, kept him from his scientific work. 
He was therefore very pleased to hand over the 
management of the property to one of my brothers 
who had just completed his studies in a Higher 
Agricultural School, and, in spite of difficult condi- 
tions, Elie had the satisfaction of giving up every- 
thing in good order. 

Thanks to my parents' inheritance, he was able 
to abandon his share of the Panassovka patrimony 
to the children of his brother and to live henceforth 
independently. He wished to pursue researches on 
the shores of the Mediterranean : therefore, in the 
autumn of the year 1882, we went to Messina with 
my two sisters and my three young brothers. The 
children were no trouble to Elie, who loved them ; 
on the contrary, he enjoyed organising the journey 
and arranging all sorts of pleasures for them. The 
children, accustomed to his kindly indulgence, always 
came to " the Prophet " for everything they wanted. 1 

1 " Elie " is the French form of Elijah, in Russian Ilia, and was ulti- 
mately adopted by Metchnikoff. 


Messina Inception of the phagocyte theory Encouragement from 
Virchow and Kleinenberg First paper on phagocytosis at the 
Odessa Congress in 1883 The question of Immunity Article in 
Virchow's Archiv, 1884. 

AT Messina, we settled in a suburb, the Ringo, on the 
quay of the Straits, in a small flat with a garden and 
a splendid view over the sea. We did not have 
much room, and the laboratory had to be installed in 
the drawing-room, but, on the other hand, Elie only 
had to cross the quay in order to find the fisherman 
who provided him with the material needed for his 
researches and with whom we frequently went sailing. 
Metchnikofi loved Messina, with its rich marine 
fauna and beautiful scenery. The splendid view of 
the sea and the calm outline of the Calabrian coast 
across the Straits delighted him. He enjoyed it all 
the more after the many excitements of life at the 
University, and eagerly gave himself up to his 
researches. Often, in later years, he delighted to 
recall memories of that period, the more so that this 
was connected with the principal phase of scientific 
activity which led to the formation of his phagocyte 
theory. After the earthquake in 1908, he wrote a 
few pages on Messina and ended his article by the 
following lines : 

Thus it was in Messina that the great event of my 
scientific life took place. A zoologist until then, I suddenly 


became a pathologist. I entered into a new road in which 
my later activity was to be exerted. 

It is with warm feeling that I evoke that distant past 
and with tenderness that I think of Messina, of which the 
terrible fate has deeply moved my heart. 

They say that Messina will be rebuilt in the same place 
but in a different way. Houses will be constructed of light 
materials, they will be low, and the streets broad. . . . 

The town will be a new Messina, not " my Messina," not 
that with which so many dear memories are associated in 
my mind, . . . 

Metchnikoff continued to study intracellular diges- 
tion and the origin of the intestine. He foresaw 
that the solution of those problems would lead to 
general results of great importance. The study of 
medusae and of their mesodermic digestion confirmed 
him more and more in the conviction that the meso- 
derm was a vestige of elements with a primitive 
digestive function. In lower beings, such as sponges, 
this function takes place without being differentiated, 
whilst with other Ccelentera and with some Echino- 
derma the endoderm gives birth to a digestive 
cavity ; yet, the mobile cells of the mesoderm pre- 
serve their faculty of intracellular digestion. As he 
studied these phenomena more closely, he ascertained 
that mesodermic cells accumulated around grains of 
carmine introduced into the organism. 

All this prepared the ground for the phagocyte 
theory, of which lie himself described the inception 
in the following words : 

I was resting from the shock of the events which provoked 
my resignation from the University and indulging enthusi- 
astically in researches in the splendid setting of the Straits 
of Messina. 

One day when the whole family had gone to a circus to see 


some extraordinary performing apes, I remained alone with 
my microscope, observing the life in the mobile cells of a 
transparent star-fish larva, when a new thought suddenly 
flashed across my brain. It struck me that similar cells 
might serve in the defence of the organism against intruders. 
Feeling that there was in this something of surpassing interest, 
I felt so excited that I began striding up and down the room 
and even went to the seashore in order to collect my thoughts. 

I said to myself that, if my supposition was true, a splinter 
introduced into the body of a star-fish larva, devoid of blood- 
vessels or of a nervous system, should soon be surrounded by 
mobile cells as is to be observed in a man who runs a splinter 
into his finger. This was no sooner said than done. 

There was a small garden to our dwelling, in which we had 
a few days previously organised a " Christmas tree " for the 
children on a little tangerine tree ; I fetched from it a few 
rose thorns and introduced them at once under the skin of 
some beautiful star-fish larvae as transparent as water. 

I was too excited to sleep that night in the expectation of 
the result of my experiment, and very early the next morning 
I ascertained that it had fully succeeded. 

That experiment formed the basis of the phagocyte theory, 
to the development of which I devoted the next twenty-five 
years of my life. 

This very simple experiment struck Metchnikoff 
by its intimate similarity with the phenomenon which 
takes place in the formation of pus, the diapedesis x 
of inflammation in man and the higher animals. The 
white blood corpuscles, or leucocytes, which consti- 
tute pus, are mobile mesodermic cells. But, while 
with higher animals the phenomenon is complicated 
by the existence of blood-vessels and a nervous 
system, in a star-fish larva, devoid of those organs, 
the same phenomenon is reduced to the accumulation 

1 Migration of the white blood corpuscles (leucocytes) through the walls 
of blood-vessels. 



of mobile cells around the splinter. This proves that 
the essence of inflammation consists in the reaction 
of the mobile cells, whilst vascular and nervous inter- 
vention has but a secondary significance. Therefore, 
if the phenomenon is considered in its simplest expres- 
sion, inflammation is merely a reaction of the meso- 
dermic cells against an external agent. 

MetchnikofE then reasoned as follows : In man, 
microbes are usually the cause which provokes in- 
flammation; therefore it is against those intruders 
that the mobile mesodermic cells have to strive. 
These mobile cells must destroy the microbes by 
digesting them and thus bring about a cure. 

Inflammation is thus a curative reaction of the 
organism, and morbid symptoms are no other than 
the signs of the struggle between the mesodermic 
cells and the microbes. 

In order to verify these conjectures, he started 
studying the englobing of microbes by mesodermic 
cells in larvae and in other marine invertebrates 
which he inoculated. 

At that time, a well-known German scientist, 
Kleinenberg, was Professor of Zoology at Messina. 
Metchnikoff imparted his ideas to him and showed 
him his experiments. Kleinenberg encouraged him 
very much ; he looked upon his theory as " an 
Hippocratic thought " and advised him to publish 
it at once. 

Metchnikoff was also greatly encouraged by 
Virchow, who happened to pass through Messina and 
came to see his preparations and his experiments, 
which seemed to him conclusive. However, Virchow 
advised him to proceed with the greatest prudence 
in their interpretation, as, he said, the theory of 


inflammation admitted in contemporary medicine was 
exactly contrary to MetchnikoS's. It was believed 
that the leucocytes, far from destroying microbes, 
spread them by carrying them and by forming a 
medium favourable to their growth. 

Metchnikofi always preserved a deep gratitude 
towards Virchow and Kleinenberg for the moral 
support which they gave him at that time. 

When the hot weather came, we left Messina for 
Biva, a delicious summer resort on the shores of the 
Lake of Garda. There, Metchnikofi wrote his first 
memoir on the reaction of inflammation and on the 
digestion of microbes by the mesodermic cells of 
lower invertebrates. On the way back to Kussia 
through Vienna, he went to see the Professor of 
Zoology, Glaus ; he found other colleagues with him 
and expounded his theory to them. They were much 
interested, and he asked them for a Greek translation 
of the words " devouring cells," and that is how they 
were given the name of phagocytes. 

Glaus asked him for his memoir for the Review 
which he edited and in which it appeared soon after- 
wards, in 1883. 1 The new-born " phagocyte theory " 
was thus very well received by naturalists and by 
Virchow, the father of cellular pathology. 

Having returned to Russia, we went to the country, 
where Elie had to attend to family business ; never- 
theless, he continued his researches in every leisure 
moment. He had observed in Echinoderma that, 
during the transformation of their larvae, the parts 
becoming atrophied were englobed by mesodermic 

1 Arbeiten des zool Inst. zu Wien, Bd. v. Heft ii. p. 141. "Unter- 
suchung iiber die intracellulare Verdauung bei wirbellosen Tieren," E. 


mobile cells. In those observations he was delighted 
to have found an example of physiological inflam- 
mation, i.e. one which presented itself in normal and 
non-morbid conditions. He thought he might observe 
it also during the metamorphosis of the tadpole into 
a frog, whilst the tail was being atrophied. But he 
found that, instead of the leucocytes of the blood, 
certain cells from the muscular tissue were those which 
devoured the enfeebled elements of the tail ; he thus 
learnt that phagocytes might be, not only the white 
blood corpuscles, but other cells of mesodermic origin. 1 

In autumn 1883 he read his first paper on phago- 
cytosis to a congress of physicians and naturalists at 
Odessa. 2 He compared the phagocytes to an army 
hurling itself upon the enemy and looked upon the 
phagocytic reaction as a defensive force of the 

In that paper itself and from that moment onwards, 
the trend of his ideas towards optimism becomes visible. 
By discovering the phagocytic reaction of the organ- 
ism, he made a first breach in his philosophy of human 
nature, hitherto so pessimistic ; he discovered within 
it a salutary element which could be utilised by 
science to combat its discords. He began to have 
some faith in the power of knowledge, not only for 
this struggle, but also for the establishment of a 
rational conception of life in general. Thus he said 
in his paper to the Odessa Congress : 

The theoretical study of Natural History problems (in 
the largest sense of the word) alone can provide a critical 

1 It was only in 1892 that he completed and developed his observations. 
He found that the cells of the sarcoplasma of the muscular tissue devoured 
its contractile part, the myoplasma. 

2 This paper was entitled " Forces curatives de 1'organisme." 


method for the comprehension of truth and lead to a definite 
conception of life, or at least allow ua to approach one. 

And yet, until then, the theory of phagocytosis 
as a curative force of the organism was but a hypo- 
thesis, for he had not yet observed spontaneous 
phagocytosis in diseases and did not know pathogenic 
microbes. He therefore sought to study them in lower 
animals, whose simple structure made the observa- 
tion easier. He found some small, transparent, fresh- 
water crustaceans, called daphnice, which were diseased 
and easy to place alive under a microscope. These 
crustaceans are often infected by a parasite fungus 
(Monospora bicuspidata), of which the spores, shaped 
like sharp needles, are introduced with food into the 
digestive tube, traverse the walls of it, and thus 
penetrate into the general cavity of the body. They 
are immediately attacked by mobile phagocytes, 
which either singly or in groups englobe them ; if the 
phagocytes succeed in digesting the spores, the 
daphnia recovers ; in the contrary case, the spores 
germinate and develop into small fungi which invade 
the organism and kill it. The recovery or death of 
the daphnia depends therefore on the issue of the 
struggle. 1 This observation gave final confirmation 
to the hypothesis of the curative forces of the organism. 

Metchnikoff was not content with observing lower 
animals but wished to study the reaction of the 
organism of mammals in infectious diseases. At that 
time, the best-known microbe was the bacillus of 
anthrax. He therefore chose that for his researches 
and ascertained that phagocytosis varied with the 
virulence of the microbes ; thus, while phagocytes did 

1 Virchow's Archiv, vol. 96, p. 177. 


not attack virulent bacteria, they attacked and 
rapidly digested attenuated bacteria. Moreover, he 
observed a very active phagocytosis in refractory 
animals and the reverse in sensitive ones. 

He thus came face to face with the question of 

He approached it by a comparative examination 
of the reaction of the organism of vaccinated rabbits 
and of non- vaccinated ones, and ascertained that an 
active phagocytosis was only manifested in a pre- 
viously vaccinated organism. Metchnikoff explained 
these facts by the theory that the phagocytes became 
accustomed, gradually, through vaccination, to strive 
against more and more virulent microbes. 

From that moment, immunity appeared to him as 
being no other than this progressive hardening. He 
published his researches in 1884 in Virchow's Archiv, 
and impatiently awaited medical reviews, hoping to 
find some answer, but the memoir passed unnoticed ; 
the full significance of it had not been grasped. 


Ill-health of his wife and sister-in-law Journey to Tangiers through 
Spain Villefranche Baumgarten criticises the phagocyte theory. 

IN 1884, Metchnikofl's work was interrupted by the 
ill-health of my eldest sister and of myself ; physicians 
considered that we had weak lungs and advised that 
we should spend the winter in the South. Elie, full 
of anxiety, hastened to take us there. 

My younger brothers were now old enough to 
remain at school in our absence so as to go on with 
their studies ; we therefore started with my two 
sisters. As cholera was raging in Italy, we went to 
Spain, hoping to find a place with a mild climate and 
conditions favourable to my husband's work. But 
we traversed the whole country without finding the 
right combination, and, as we had come too far to 
go back, we decided to spend the winter on the 
African coast, at Tangiers, close to Gibraltar where we 

Metchnikofi had not much taste for sight-seeing, 
but, with his inquisitive and observing mind, liked to 
understand what he saw, and never failed to acquaint 
himself with the history of the countries which we 
traversed and which, with his ever-ready solicitude, he 
wanted us to see. We therefore saw every interesting 
town on our route through Spain. In the evenings we 
read together works on the history and art of the 



country, and in the day-time we went for long rambles 
in order to examine all that there was to see. The 
history of the country, full of the sombre fanaticism 
which is reflected in its art, the austere aridity of the 
central plateau of the land, the reserved temper of 
the population none of that found any echo in the 
vibrating, sunlight-loving soul of Metchnikoff. 

Gentle Italy, her exuberant life and highly-cultured 
past, charmed him much more. He was conse- 
quently better pleased with Southern Spain, which 
is more similar to Italy. He was greatly impressed 
by the grandiose site and luminous atmosphere of 
Granada and the Alhambra and by the superb gardens 
of Malaga, with their tropical plants and avenues of 
palm trees. 

At Gibraltar, he was greatly interested as a zoo- 
logist in the only monkeys (Macaques or Barbary 
apes) which have remained wild in Europe ; he never 
tired of watching their habits whilst those amusing 
creatures jumped from tree to tree above our heads. 

He had ample leisure to do so, fora frightful tempest 
kept us at Gibraltar, preventing the crossing of the 
Straits. As Metchnikoff was very anxious to set to 
work, we took the first steamship which ventured out, 
but the sea was still running so high that our ship 
was damaged and we had to go back. A panic 
took possession of the passengers, during which my 
sisters and I were struck by the calmness of Elie, 
who did not seem to realise the danger. After a delay 
of a few days, we were at last able to cross. 

Our first impression of Tangiers, an Arab port of 
a thoroughly Oriental type, was extremely vivid. 
The city lay before us with its tall minarets and flat 
roofs, shining white under the burning sun. The 


steamer dropped anchor some distance from the land- 
ing stage, and we were taken ashore on small boats, 
immediately to be surrounded by a motley crowd with 
faces varying from the pale olive of the pure Arab 
to the coal-black of the negro. All these people, in 
brilliant and picturesque garments, were shouting, 
gesticulating, fighting for the possession of passengers 
and their luggage, dragging them into the boats or 
carrying them on their backs, themselves standing 
up to their waists in water. 

That feverish agitation, noise, and glaring sun- 
light introduced us suddenly to new and violent 

Already at Gibraltar, Metchnikoff had made 
arrangements with a Spanish-speaking Arab from 
Tangiers who undertook our installation. He provided 
us with a very primitive dwelling, himself serving as 
our guide, cook, and general factotum. 

We hastened to look for zoological material : 
alas, the sea was almost a desert. After a long 
search we only found a few rare sea-urchins, and 
Metchnikofi had to content himself with this meagre 
fauna during the whole of the winter. He resigned 
himself to the study of the embryology of sea-urchins 
in order to fill a few lacunae in his previous researches. 
As he could not work much for lack of materials, he 
came with us for long excursions, during which he 
used to improvise interminable and very amusing 
tales with which to entertain my little sister. 

At the beginning of our stay we were greatly 
interested by the life and customs of the country. 
The picturesque and varied crowd, the dignified and 
biblical types of Arabs, the bronzed Berbers, negroes, 
fanatical sects of Aissawas, snake-charmers, the jousts, 


and mad races of cavalry across the sandy beach; 
opium smokers ; mysterious silhouettes of veiled 
women; the call to prayer from the tall minarets 
all that strange and exotic life fascinated us. 
But after a time the wild customs, continual shout- 
ing on the occasion of every ceremony, vendettas, 
cruel fanaticism, and also the absolute lack of in- 
tellectual resources, began to tell on our nerves. 
Inactivity weighed heavily upon Metchnikoff ; never- 
theless, he bore his ill-luck with his usual courage 
and gaiety, finding great consolation in the excellent 
influence that the climate of Tangiers had upon all 
our healths. 

At last, in the spring, we started for Villefranche, 
where he immediately set to work with success upon 
the embryology of jelly-fish ; an important mono- 
graph on that subject was published by him in 1886. 
In it he gave definite form to his theory of the phago- 
cytella and the genetic relationships of animals and 
of their primitive organs, a theory already mentioned 
above (p. 110). 

From Villefranche we went to Trieste, where 
Metchnikoff studied star-fish and filled the lacunae in 
his researches on the origin of the mesoderm. 

In a medical review which he read at Trieste, he 
found the first account of his phagocyte theory ; 
it was an unfavourable and hostile criticism by a 
German scientist of the name of Baumgarten, en- 
deavouring to prove that Metchnikofi's deductions 
were inadmissible. This grieved and pained him very 
much, but he immediately recovered himself and 
strongly determined to study the medical side of the 
question in order to prove on that ground that his 
theory was well-founded. 



A Bacteriological Institute in Odessa Unsatisfactory conditions 
Experiments on erysipelas and on relapsing fever. 

THE results of Pasteur's antirabic inoculations were 
published in 1885. The Municipality of Odessa, 
desirous of founding a bacteriological station in that 
town, sent Dr. Gamaleia to Paris to study the new 
method. Metchnikofi was appointed Scientific Direc- 
tor of the new institution, and Drs. Gamaleia and 
Bardach, former pupils of his, were entrusted with the 
preparation of vaccines and preventive inoculations. 
The Institute, opened in 1886, was founded at the 
expense of the Municipality of Odessa and of the 
Zemstvo of the Kherson Province. 

Metchnikofi himself describes as follows the short 
time he spent in that Institute : 

. . . Having given up my State work, I placed myself 
at the service of the city and the Zemstvo. 

Absorbed as I was by the scientific part of the work, I 
confided to my young colleagues the practical part, i.e. the 
vaccinations and the perfection of vaccines. 

It was to be supposed that all would go very well. 

Work hi the new Institute began with ardour. But, very 
soon, a strong opposition manifested itself against it. 

The medical administration began to make incursions into 
the Institute, with a view to finding some infractions of the 

Medical society was hostile to every work which issued 



from the laboratory. The institutions which had subscribed 
funds for the Institute were demanding practical results, 
while all necessary work towards that object was met by 
every sort of obstacle. 

For instance, in order to destroy certain voles, very 
harmful to the cereals of Southern Russia, we proposed to 
make experiments as to infecting those rodents with the 
microbe of chicken cholera. Laboratory experiments were 
begun with that object. But, one day, I received an order from 
the Prefect peremptorily forbidding those experiments. This 
measure had been taken at the instigation of local physicians ; 
having seen in a Petersburg newspaper an article by some 
one who had not a notion of bacteriology, they had assured 
the Prefect that chicken cholera could turn into Asiatic cholera. 

I had to appeal to the General Governor, who ended by 
countermanding the Prefect's order ; nevertheless this incident 
was not without regrettable consequences concerning the 
ulterior activities of the Institute. 

Apart from all that, a deep scission took place between the 
members, though they were so few, of the Institute itself, and 
this had fatal consequences. 

The men who were in charge of the practical work ceased 
to work in concert ; I could not take their place, being over- 
whelmed with scientific researches, besides which, holding no 
medical degree, I was not qualified to perform vaccinations 
on human beings. 

Under those conditions, I understood that in my quality 
as a theoretician, I should do well to retire, leaving the 
laboratory to practitioners who, bearing full responsibility, 
would fill the part better. 

During his stay at the Odessa Bacteriological 
Institute, MetchnikofE had busied himself with infec- 
tious diseases in order to answer the first objections 
to his theory. He began by the microbes of erysipelas 
and showed that the phenomena of the disease, as 
well as those of recovery, were in full accord with 
the postulates of the phagocyte theory. 


And then he studied relapsing fever in order to 
answer Baumgarten's objections, affirming that there 
was no phagocytic reaction in that disease, though it 
almost invariably ended in recovery. Experiments 
on man not being possible, Metchnikoff procured 
some monkeys, which he inoculated with relapsing 
fever, and ascertained that Baumgarten's error was 
due to the fact that he had only looked for phago- 
cytosis in the patient's blood, whilst it really took 
place in the spleen. 

These researches on erysipelas and relapsing fever 
were published in Virchow's Archives in 1887. Besides 
this scientific work, he was also giving lectures on 
bacteriology to some physicians, and was in full pro- 
ductive activity when external opposition and the 
discord among his collaborators in the Institute itself 
forced upon him the conviction that he could remain 
there no longer. 

At that very moment the Prince of Oldenburg, 
having founded a Bacteriological Institute at Peters- 
burg, invited Metchnikoff to take charge of it. He 
had to refuse, fearing the Northern climate for my 
health, and knowing from experience that it was 
impossible for a layman to manage an Institute with 
a medical staff. Yet he could not do without a 
laboratory. Seeing no possibility of having one in 
Russia, he decided to look abroad for a refuge and a 

" Having learnt from experience at Odessa," he 
wrote, " how difficult was the struggle against an 
opposition coming from all sides and devoid of 
reasonable causes, I preferred to go abroad to look 
for a peaceful shelter for my scientific researches." 

We were no longer held back by family considera- 



tions ; our links with Russia had gradually loosened. 
He had resigned from the University, discord reigned 
at the Odessa Bacteriological Institute, conditions of 
life in Russia were very unfavourable to scientific 
activity ; in a word, " obstacles from above, from 
below, and from all sides," as MetchnikofE expressed 
it, gradually led to his resolution to leave his native 


Hygiene Congress in Vienna Wiesbaden Munich Paris and Pasteur 
Berlin and Koch Failure of anthrax vaccination of sheep 
Decision to leave Russia. 

IN 1887 we went to Vienna, where a Congress of 
Hygienists was held, in which, for the first time, 
bacteriologists took part. Metchnikofi thus had the 
opportunity of becoming acquainted with many of 
them and to make inquiries concerning bacteriological 
laboratories. Professor Hueppe, of Wiesbaden, very 
kindly invited him to come to work in his own. The 
idea pleased Metchnikoff, who thought that a peaceful 
little University town would be very favourable to 
his work. But he found that his situation would be 
very difficult at Wiesbaden on account of the lack of 
harmony between the different laboratories in the 
town ; he therefore gave up the project which had 
seemed to him so tempting. 

By this time many objections had been raised 
against the phagocyte theory, and, Emmerich having 
attacked him very violently, Metchnikofi went to 
Munich to have an explanation with him. This gave 
him the opportunity of realising that Munich, like 
Wiesbaden, was not a place where he would care to 

He had a great desire to know Pasteur and his 
collaborators, who had just been playing such an 



important scientific part, and, finding ourselves within 
easy reach of Paris, we repaired thither, without the 
slightest idea of settling there. This is how Metchni- 
koff himself described his first interview with Pasteur : 

On arriving at the laboratory destined for the antirabic 
vaccinations, I saw an old man, rather undersized, with a 
left hemiplegia, very piercing grey eyes, a short beard 
and moustache and slightly grey hair, covered by a black 
skull-cap. His pale and sickly complexion and tired look 
betokened a man who was not likely to live many more years. 
He received me very kindly, and immediately spoke to me of 
the question which interested me most, the struggle of the 
organism against microbes. 

" I at once placed myself on your side," he told me, " for I 
have for many years been struck by the struggle between 
the divers micro-organisms which I have had occasion to 
observe. I believe you are on the right road." 

Pasteur at that time was chiefly occupied with 
antirabic vaccinations and with the building of a 
new Institute in the rue Dutot. Seeing the vast 
dimensions of the edifice and learning that the 
scientific staff was not large, Metchnikoff asked 
Pasteur if he might hope to work in one of the labora- 
tories in an honorary capacity. Pasteur not only 
acceded to this request but offered him a whole 
laboratory. He was most kind, invited us to his 
home and introduced Metchnikoff to his collaborators, 
who produced an excellent impression on my husband. 

Though all this made him incline more and more 
towards the Pasteur Institute, he still dreaded life 
in a large and noisy city, thinking that a peaceful 
little University town would be more favourable to 
his work. Therefore, before making a final decision, 
he desired to visit a few more bacteriological labora- 


On our way back we passed through Berlin, where 
Metchnikoff wished to see Professor Koch and to 
show him some interesting specimens of phagocytosis. 
The great savant received him very coldly. For a 
long time, while examining specimens of the spleen in 
relapsing fever, he refused to recognise in them an 
example of phagocytosis. Though he was at last 
obliged to bow to evidence, he yet remained unfavour- 
able to the phagocyte theory, and all his assistants 
followed his example. MetchnikoS was much sur- 
prised and grieved by this hostility towards his 
ideas, notwithstanding that they were based on well- 
established facts. We hastened to leave Berlin. 

Many years later, when phagocytosis was generally 
admitted, even in Germany, Professor Koch and many 
other German scientists welcomed Metchnikofl very 
kindly, which somewhat counterbalanced the un- 
pleasantness of early memories. But, at that time, 
the contrast between our impression of Paris and of 
Germany was so great that all hesitation was at an 
end : the choice was made. 

On returning to Odessa, Metchnikofi began to 
prepare his resignation and his departure. Yet he 
still had time to make some researches on phago- 
cytosis in tuberculosis, in reply to the objections 
which rained upon his theory. 

In the spring, he handed over the direction of the 
Institute to Dr. Gamaleia and took leave ; we went 
to the country for a while before our final departure. 
During that time, Drs. Gamaleia and Bardach were 
majdng anthrax vaccinations on a large scale in a 
vast private property in the province of Kherson. 
When we were settled in our country home, Metch- 
nikoff received a telegram announcing that the first 


anthrax vaccine had killed many thousand sheep. 
Though, as a matter of fact, his personal responsibility 
was not involved, the blow was a terrible one; he 
hastened back to Odessa to elucidate the cause of 
the catastrophe. But it remained obscure. . . . 

This painful episode was the last drop which made 
the cup brim over ; it strengthened Metchnikoff in 
his resolve to leave Russia. 


The Pasteur Institute Dreams realised Metchnikoff at fifty Growing 
optimism Attenuated sensitiveness The Sevres villa Daily 

HAVING decided to settle in France, we hastened to 
make ourselves acquainted with contemporary French 
literature, thinking to find in it a reflection of the 
soul and manners of the nation. But the realistic 
literature of the time, in spite of the great artistic 
worth of many of the authors, gave us an erroneous 
idea of life in France, of which it represented but one 
of many aspects. It was therefore with apprehension 
that we asked ourselves if we should ever be able to 
adapt ourselves to the new conditions, and whether 
our isolation would not be great. 

We arrived in Paris on the 15th of October 1888, 
and we lodged at a small hotel in the Latin quarter, 
not far from the rue d'Ulm where the old Pasteur 
Institute stood, the new one not being completed. 
There was but little room in the laboratory, and 
Metchnikoff felt rather uneasy, fearing that he was 
in the way. But the new Institute soon was suffi- 
ciently advanced for him to settle there. 

He was given two rooms on the second floor ; I 
served as his assistant ; he was perfectly happy at 
being at last able to give himself up in peace to his 
work. Soon, young physicians came to work under 



his direction. Their number having increased, he 
was given a whole floor in which to instal them, 
two rooms on that floor being reserved for his own 
use. He occupied these rooms until the end of his 

His dreams were at last realised. This is from 
a narration of the causes which led to his departure 
from Russia, in his own words : 

Thus it was in Paris that I succeeded at last in practising 
pure Science apart from all politics or any public function. 
That dream could not have been realised in Eussia because 
of obstacles from above, from below, and from all sides. One 
might think that the hour of science in Russia has not yet 
struck. I do not believe that. I think, on the contrary, 
that scientific work is indispensable to Russia, and I wish from 
my heart that future conditions may become more favour- 
able than in the time of which I have spoken in the above 

Soon he was able to appreciate the great French 
qualities : humanitarian manners, tolerance, and gentle- 
ness, real freedom of thought, loyal and courteous 
intercourse, all of which made life easy and agreeable. 
And most precious of all were the true friendships 
which he contracted with his colleagues and his 
pupils. Indeed the Institut Pasteur and France 
became for him a second Motherland, and when in 
later years he was invited to other countries with 
more liberal conditions, he habitually replied that 
only for one place would he leave the Pasteur Institute, 
" the neighbouring cemetery of Montparnasse." 

However, after his death, the Pasteur Institute 
which he had so loved continued to give him hos- 
pitality and harboured his ashes. . . . 


Pasteur himself ever was most kind and helpful 
to Metchnikofi. During the first years, when his 
health still allowed it, he used often to come to the 
laboratory, questioning Metchnikofi: on his researches 
with much interest and always warmly encouraging 
him. He even attended assiduously his course of 
lectures on inflammation. After his state of health 
no longer allowed him to go out, MetchnikofE used 
to visit him every day, and tried to cheer him by 
talking to him of current researches. 

MM. Duclaux and Roux became his closest friends ; 
they were at first brought together by scientific 
interests and by questions concerning the Institute ; 
but, gradually, personal sympathy grew up between 
them, binding them by that solid bond which is made 
up of daily occurrences, inducing respect, confidence, 
and affection. Moreover, Metchnikoff felt the deepest 
gratitude towards Pasteur and his collaborators, who 
had given him the possibility of working in so favour- 
able an atmosphere. 

From the very first, Pasteur sympathised with the 
phagocyte theory ; the other members of the Institute 
thought it too biological, almost vitalistic. But when 
they had made themselves thoroughly cognisant with 
it, they also adopted it. Thus, having found in the 
Pasteur Institute not only favourable working condi- 
tions but also moral support, Metchnikofi: became 
deeply attached to it, and the interests of " the House " 
became his. 

In 1915, on the occasion of MetchnikofTs seventieth 
anniversary, M. Roux, in a Jubilee speech, gave of 
him and of his work the following appreciation which 
describes, better than anything I could say, what his 
part was in the Pasteur Institute : 


In Paris as in Petrograd, as in Odessa, you have become 
a leader of thought, and you have kindled in this Institute a 
scientific focus which has radiated afar. 

Your laboratory is more alive than any in the house ; 
workers come to it in crowds. There, the bacteriological 
events of the day are discussed, interesting preparations 
examined, ideas sought for that may help an experimenter 
to solve difficulties in which he has become involved. It is 
to you that one comes to ask for a control experiment on a 
newly observed fact, for a criticism of a discovery that does 
not always survive the test. 

Moreover, as you read everything, every one comes to you 
for information, for an account of a newly published memoir 
which there is no time to read. It is much more convenient 
than to consult the library and also much safer, for errors of 
translation and interpretation are avoided. 

Your erudition is so vast and so accurate that it is made 
use of by the whole house. How many times have I not 
availed myself of it ? One never fears to take advantage of 
it, for no scientific question ever finds you indifferent. Your 
ardour warms the indolent and gives confidence to the 

You are an incomparable collaborator as I know, I who 
have had the good fortune of being associated with your 
researches on several occasions. Indeed, you did nearly all 
the work ! 

More even than your science, your kindliness attracts ; 
who amongst us has not experienced it ? I have had a 
touching proof of it when, many times, you have nursed me 
as if I were your own child. You are so happy in doing 
good that you even feel gratitude towards those whom you 

This is such an intimate gathering that I may be allowed 
to say quite openly that it is so painful to you not to give 
that you prefer being exploited rather than close your hand. 

The Pasteur Institute owes you much ; you have brought 
to it the prestige of your renown, and by your work and that 
of your pupils you have greatly contributed to its glory. You 


have given a noble example of disinterestedness by refusing 
any salary in those years when the budget was balanced 
with difficulty and by preferring to the glorious and lucrative 
situations that were offered to you the modest life of this 
house. Still a Russian by nationality, you have become 
French by your choice, and you contracted a Franco-Russian 
alliance with the Pasteur Institute long before the diplomats 
thought of it. 

At the beginning the members of the Pasteur 
Institute were few, and the association bore a quasi- 
family character, Pasteurians often being compared 
with a monastic order, united by the worship of 
science. The progressive growth of the Institute 
inevitably destroyed its character of intimacy, but it 
remained a precious scientific focus, and this is what 
Metchnikofi said of it in 1913, apropos of the twenty- 
fifth anniversary of its foundation : 

If we weigh the for and against of the Pasteur Institute, 
it is indisputable that the first surpasses the second by a 
great deal. I do not think another institution exists that is 
equally favourable to work. Innumerable proofs have been 
adduced to attest this in the twenty-five years that our 
House has existed. 

It was especially the development of pure scientific 
research in the Institute which interested Metchni- 
kofi ; he continually considered means of contributing 
towards it ; he thought it necessary to attract active 
scientific forces regardless of their origin, to institute 
generous scientific " scholarships," and to stimulate 
by every means scientific activity and spirit. 

As the rapid development of bacteriology necessi- 
tated having recourse to chemistry, physics, and 
physiology, he considered it indispensable to organise 
collective work in which specialists in these divers 
branches should take part, thus collaborating to the 


solution of the same problem. Later he was able to 
realise this project, up to a certain point, in his own 
laboratory, when studying intestinal flora. 

He thought it would be useful to extend this 
method, as far as possible, to researches such as that 
on tuberculosis and on cancer, such researches being 
complicated and protracted and demanding co-ordinate 
efforts and an organisation that should prevent the 
repetition of individual first steps. A clinic attached 
to the Pasteur Institute and adapted to scientific 
researches seemed to him indispensable. 

He also considered that the experimental study 
of those human diseases which can only be inoculated 
in anthropoid apes should be carried out through 
the breeding of those animals in the colonies, for 
infantile diseases demand very young apes as subjects 
for experiments, and they cannot be brought to Europe 
in sufficient numbers without great loss. A mission 
of workers might carry out experiments on the spot. 

He thought the popularisation of science a very 
useful thing and wished the Pasteur Institute to 
participate in it by appropriate courses of public 
lectures. He attached great importance to the pene- 
tration into ordinary life of results acquired by science, 
for the struggle against disease consists chiefly in 
prophylactic and hygienic measures which can only 
be applied by a well-informed public. For that 
reason he was always willing to be interviewed on 
scientific questions by journalists and, indeed, by any 
one, however ignorant. In order to instruct the public 
he often wrote popular articles on questions of hygiene 
and medicine. 

Science in general never was a dead letter for him ; 
'his most abstract conceptions were always narrowly 


bound to life ; he saw one through the other and 
considered that they should serve each other. 

Apart from scientific researches, he took part in the 
courses given at the Pasteur Institute. He prepared 
his lectures with infinite care, and, in spite of his long 
experience, he never could give them without some 
nervousness, especially during the last years of his 
life. He used even to write down the first sentences 
and to read them out in order to give himself time to 
recover ; but very soon his self-control would return, 
and he would proceed with animation and lucidity ; 
his lectures were living and suggestive. 

I have mentioned above Roux's masterly appreci- 
ation of his influence at the Pasteur Institute. The 
following was written to me, a year after MetchnikofE's 
death, by one of his closest disciples and collaborators, 
and describes in a vivid manner the deep feelings 
with which he inspired his pupils : 

" You say that you love to think that he continues to live 
in others. Could it have been otherwise ? A character as 
powerful as his is capable of influencing and illuminating the 
life, not of one individual, but of a whole generation. I look 
upon it as the greatest good fortune of my life that I was 
able to spend my best years in his orbit and to impregnate 
my mind with his spirit, not his scientific spirit, but that 
which he manifested in facing hie and humanity. 

" This bond has become so much part of myself that my first 
impulse is always to act in the way he would have approved. 
I even feel the need to share with others what I received from 
him. I do not know whether it will be given to me to solve 
certain problems posed by him, but I have the conviction 
that his spirit, in its purity, will be preserved among us. He 
will ever live in those who worked by his side, and in those 
who will come to work in his laboratory. It cannot be 


Metchnikoff on his part never remained indifferent 
to his pupils. His solicitude towards them was warm, 
sometimes paternal, always ready and active. Many 
of his pupils remained his friends and collaborators 
for years afterwards. His fiery and exclusive tem- 
perament, however, made him take up a very different 
attitude in exceptional cases, when he found himself 
in front of one who persisted in a path which Metchni- 
koff himself considered the wrong path, or before an 
action which he thought disloyal or work done with- 
out conscience. Then he became beside himself, and 
positively dangerous to those who had exposed them- 
selves to the paroxysm of his indignation. 

Fortunately such cases were rare ; as a general 
rule, the atmosphere of his laboratory was impregnated 
with scientific spirit and ardour ; all forces in it con- 
verged towards the same goal, being bound together 
by a community of aspirations and activity of which 
he was the soul. 

The first period of his life in France was taken up 
by the strengthening and development of the phago- 
cyte theory and by an eager struggle in its defence. 
He displayed in it his full energy as a scientist and 
a fighter, and this was perhaps the most agitated, 
the most tense period of his life. 

When at last his theory was securely established 
and began to be accepted, he continued his researches 
with the same passionate ardour but in an atmosphere 
of peace. It was joy and bliss to him to be able to 
work apart from other preoccupations, and the years 
of his life between fifty and sixty were the happiest 
he ever had. 

The state of his soul and his ideas had considerably 


evolved in the course of years ; the great moral and 
physical sensitiveness which had so often made him 
miserable in his youth had decreased and he had 
become much less impulsive. Unpleasant sensations 
no longer caused him so much suffering ; he could 
bear the mewing of a cat or the barking of a dog ; 
personal vexations no longer made him take such a 
horror of life as to wish to be rid of it : he now merely 
tried to conquer them. 

At first this change operated less upon his ideas 
than upon his sensations and sentiments. Accustomed 
as he was to analyse his emotions, he realised the 
development within himself of a new sense of appre- 
ciation ; less sensitive now to extreme impressions, 
he had become more so to ordinary ones. For 
instance, though less enchanted by music, and less 
irritated by discordant noises, he enjoyed absolute 
calm more fully. Now indifferent to rich food, which 
he formerly used to enjoy, he appreciated simple fare, 
bread and pure water. He did not seek for picturesque 
sites but took infinite pleasure in watching the growth 
of grass or the bursting of a bud. The first halting 
steps or the smile of an infant charmed and delighted 

Demanding less from life, he now appreciated it as 
it was, and experienced the joy of mere living. The 
instinct, the sense of life had been born in him. He 
now saw Life and Nature under a different aspect 
from that which they had borne for him in his youth, 
for he had gradually acquired more balance ; he had 
become adapted. 

In their turn, his ideas evolved towards a more 
optimistic conception of life. His reflections, freed from 
the yoke of his juvenile sensitiveness, tended towards 


the possibility of a correction of the disharmonies 
of human nature through knowledge and will. This 
evolution had taken years. " In order to understand 
the meaning of life," he said, " it is necessary to live 
a long time, without which one finds oneself in the 
position of a congenitally blind man before whom 
the beauties of colour are spread out." 

During the twenty-eight years that he lived in 
France, nearly all his time was devoted to the labora- 
tory. Whilst the Institute was still in its beginning, 
work there was calm and collected ; but, as its 
growing renown attracted many people, this quietude 
decreased considerably. Metchnikoff felt this, but 
could not bring himself to refuse to admit those who 
came ; he compensated himself by peaceful Sundays 
and holidays. 

For a long time we inhabited the neighbourhood 
of the Institute and spent the summers at Sevres ; 
in 1898 we bought a small villa there with a sum 
of money which we inherited from an aunt. In 1905 
we settled there altogether, for Metchnikoff, confined 
in the laboratory all day, felt the need of fresh air ; 
the daily walk that he was obliged to take to reach 
the house and the absolute calm, away from the noise 
of the city, suited him ; he even fancied that the hill 
on which the house was built provided him with a 
wholesome exercise for his heart. 

The return to Sevres, which he greatly liked, was 
to him a daily source of pleasure. I can see him now, 
hastily coming out of the train, his pockets full of 
papers and brochures which he read in the train and 
parcels in his hands, for he loved to bring home little 
presents. A kindly smile illumined his face and he, 


never failed to express the pleasure he felt at coming 
home. " How pure the air is ! How green the grass ! 
What peace ! You see, if I did not go to Paris to work 
I should not be so alive to the charm of Sevres and the 
pleasure of rest." He used to come home at seven and 
do no more work ; it was his daily rest. He then gave 
himself up to complete relaxation, joked, related the 
incidents of the day, spoke of his researches, planned 
experiments for the next day, read aloud part of the 
evening and then listened to music, not only because 
he liked it, but also because he wanted to " switch 
on to another line," i.e. rest his mind completely. 

He was an incomparable companion, always alive 
and communicative, generously giving out the trea- 
sures of his heart and his intelligence. He liked a 
simple life ; all artifice, all convention displeased 
him. He disliked luxury in his person to that 
extent that he never consented to possess a gold 
watch nor any object with no particular use. His only 
luxury was to gratify others. He enjoyed peaceful 
family life and a circle of intimate friends. Yet, 
appreciating as he did all serious manifestations of 
life, he was glad to have the opportunity of meeting 
people who were interesting either in themselves or for 
the knowledge which they could impart. 

In Life as in Science he found precepts to help 
the evolution of his moral and philosophical ideas, 
which he placed in their turn at Life's service. If he 
could not solve a problem, he at least pointed out its 

His attentive penetration of things in themselves, 
coupled with a creative imagination, was the force 
which enabled him to open out new prospects and 
new paths. 



On looking back upon his own life, he used to say 
that the period spent at the Pasteur Institute had 
been the happiest, the most favourable to his scientific 
work ; he therefore remained deeply attached to it 
until the end of his life. 


Opposition to the phagocyte theory Scientific controversies Experi- 
ments in support of the phagocyte theory Behring and anti- 
toxins The London Congress Inflammation. 

As long as Metchnikoff was but a zoologist, the 
scientific atmosphere around him remained calm and 
serene. But everything changed suddenly when he 
entered the domain of pathology with his theory of 
phagocytes and phagocytosis. 

Here was the realm of secular traditions, deeply 
rooted, and of theories generally admitted but resting 
on no biological basis. Attacks and objections against 
his theories came following upon each other with a 
rush, only to be compared with the racing clouds of a 
stormy sky or the hurrying waves of a tempestuous 
sea. An epic struggle began for Metchnikoff which 
was to last for twenty-five years, until the moment 
when the phagocyte theory, his child now grown 
up, emerged victoriously. To each attack, to each 
objection, he answered by fresh experiments, fresh 
observations annihilating objections ; his theory was 
assuming a wider and wider scope, becoming more 
solid, more convincing. . . . But only his intimates 
knew how much the struggle cost him in vital force, 
what sleepless nights, due to continuous cerebral 
tension and to the effort to conceive some new and 
irrefragable experiment, what alternations of hope 



and depression. ... In an ardent, stormy life such 
as this, each year counted for many. 

As soon as he arrived at the Pasteur Institute 
he undertook active researches with the object of 
developing and defending the phagocyte theory. 

By experiments on the rouget of pigs he refuted 
the objections of Emmerich, who affirmed that, in 
that disease, the destruction of the microbes was not 
due to phagocytes. By experiments on the anthrax 
of pigeons he answered the attacks of Baumgarten 
and his pupils. To Behring, who affirmed that 
immunity was due to the bactericidal power of the 
serum, he replied by a series of experiments on the 
anthrax of rats. 

By all these researches Metchnikofi proved that 
recovery and immunity depended on the absorp- 
tion and digestion of living, virulent microbes by 
phagocytes. Natural or artificial vaccination by 
attenuated microbes allows the phagocytes to become 
gradually accustomed to digest more virulent ones, 
and this confers immunity upon the organism. That 
phenomenon is comparable to that by which we can 
accustom ourselves gradually to doses of poison which 
would be very harmful if taken at the start (arsenic, 
opium, nicotine, etc.). 

Little by little, the accuracy of MetchnikorTs obser- 
vations began to be realised, and, moreover, other 
scientists supported him by their personal investi- 
gations. The part played by phagocytosis was 
becoming more and more evident and the question 
was ripening in France and in England, but in Ger- 
many it still met with great opposition. 

At the Berlin Congress in 1890 the theory was 
received very favourably by Lister, whilst Koch 


attacked it, trying to prove that phagocytes played 
no part in immunity, which, according to him, 
depended upon the chemical properties of the blood. 

Soon after that, Behring discovered antitoxins, 
and this seemed to favour the chemical or humoral 
theory of immunity. According to the latter, microbes 
and their poisons were rendered harmless by the 
chemical properties of the blood serum, properties 
similar to those of disinfecting substances. 

In spite of his firm conviction of the solidity of the 
phagocyte theory, this discovery was a shock to 
Metchnikoff, for it was in apparent contradiction with 
the cellular theory of immunity. He hastened to 
undertake a series of researches ; his overflowing 
eagerness infected his whole circle, every one taking 
the warmest interest in the progress of his experi- 

This was just as preparations were being made to 
take part in the London Congress, where the question 
of immunity was to be debated and had indeed been 
placed at the head of the programme. Many papers 
were being prepared, and a veritable tourney of 
opinions was to take place at this Congress. 

Metchnikoff had already been to England once, 
in the spring of 1891, on the occasion of his reception 
as an Honorary Doctor by the University of Cam- 
bridge. This gave him the opportunity of making 
closer acquaintance with the English, who inspired 
him with great sympathy ; years only increased this 
feeling. He appreciated the originality of their 
earnest and generalising spirit, their loyalty and 
energy ; he was grateful to them for the attentive 
and favourable attitude with which his scientific 
work and himself had been received. 


He was therefore delighted that this Congress, 
which was to be the scene of his final struggle against 
his contradictors, should take place in England and 
not in Germany, a country hostile to his ideas. 

In view of the importance of the coming debate, 
a series of fresh experiments was made. This time 
Metchnikoff undertook them not only in person, but 
also in collaboration with M. Roux and with some 
students. The whole laboratory was in a state of 

The principal papers to be read at the Congress 
on the question of immunity were those of Messrs. 
Roux and Biichner, the first entirely in favour of the 
phagocyte theory and the second supporting the 
humoral theory. 

Metchnikoff read an epitome of his researches and 
of his answers to attacks on his theory. Towards the 
end of the Congress the latter had visibly acquired 
the suffrage of numerous scientists. Roux wrote to 
me from London concerning my husband's paper : 

Metchnikoff is busy showing his preparations and, besides, 
he would not tell you how great is his triumph. He spoke 
with such passion that he carried everybody with him. I 
believe that, this evening, the phagocyte theory is the richer 
by many friends. 

Thus the researches made in recent years and the 
results of the London Congress allowed us to consider 
the phagocyte theory of immunity as being solidly 

Yet, Behring's discovery of antitoxins still hung 
over it like a sword of Damocles ; it was imperative 
that the respective parts played by antitoxins and 
by phagocytes should be elucidated. With that 


object in view, Metchnikofi undertook new researches 
and succeeded in ascertaining once for all the narrow 
link between immunity and the function of the 
phagocytes which probably elaborate the antitoxins 
as a product of their digestion of vaccinal toxins. He 
drew this conclusion from the fact that, in a rabbit 
vaccinated against hog-cholera, the exudate devoid 
of phagocytes l is neither bactericidal, nor antitoxic, 
nor attenuating, while it is so if it contains phagocytes. 
Therefore a relation of causality exists between cells 
and the acquired properties of humors. And the 
resistance of the animal is in visible correlation with 
the degree of phagocytosis which is manifested by it. 

These results having been established, it seemed 
as if the last rampart of the humoral theory had been 
taken by storm. 

In the meanwhile the persistent and bitter opposi- 
tion of physicians to the phagocyte theory made a 
great impression on Metchnikofi, and, while stimu- 
lating his energy in defence of his ideas, it maintained 
him in a state of nervous excitement and even 
depressed him. 

He asked himself why this obstinate opposition 
to a doctrine based on well-established facts, easily 
tested and observed throughout the whole animal 
kingdom ? To him, a naturalist, it seemed clear and 
simple and all the more admissible that it was con- 
firmed by the generality of its application to all 
living beings. 

But, he thought, perhaps the real cause of the 
attitude of the contradictors lies in the very fact 
that medical science only concerns itself with the 
pathological phenomena of higher animals, leaving 

1 Aqueous humor, the exudate of aseptic redemata. 


their evolution entirely out of account, as well as 
their starting-point in lower animals whilst it is 
the very simplicity of the latter which allows us to 
penetrate to the origin of the phenomena. 

Perhaps a general plan of the whole, in the shape 
of a comparative study, embracing the whole animal 
scale, would throw light over the generality of phago- 
cytic phenomena and would make their continuity 
understood through normal and pathological biology. 
He determined to make this effort. In order to place 
in a fresh light the biological evolution of phagocytosis 
phenomena in disease, he chose one of the principal 
manifestations of pathological phagocytosis, inflam- 
mation, and, in 1891, gave a series of lectures on this 
subject which he afterwards published in a volume. 
According to his usual method, he began by the 
most primitive beings, taking as a starting-point the 
lower organisms which do not yet possess differentiated 
functions, and whose normal digestion is, if necessary, 
used as a means of defence against noxious agents. 
Then, by a comparative study in every grade of 
the animal kingdom, he proved that the same mode 
of struggle and defence persists in the mesodermic 
cells, the phagocytes in all animals in general. 
In all of them, thanks to a special sensitiveness, 
Chimiotaxis, phagocytes move towards the intruder, 
to englobe it and digest it if they can. This reaction 
for defence by the organism takes place in beings 
endowed with a vascular system by the migration 
of the blood-phagocytes which traverse the walls of 
the blood-vessels in order to betake themselves to 
the invaded point. 

In higher animals, all the symptoms which accom- 
pany this phenomenon of defence and which constitute 


the classical picture of inflammation (a heightened 
temperature, pain, redness, tumefaction) are due to 
the complexity of the organism ; but the essence, the 
primum movens of inflammation, with them also, is 
a digestive action of the phagocytes upon the noxious 
agent, therefore a salutary reaction of the organism, 
essentially similar to the normal digestion of inferior 
beings. Metchnikofi adduced numerous examples 
giving evidence of the genetic link which exists 
between inflammation and normal intracellular 
digestion, and while establishing the evolution of 
the former on biological and experimental bases, he 
showed at the same time the close connection which 
binds normal biology and pathological biology. 

This series of lectures formed a volume which 
appeared in 1892 under the title of Legons sur la 
pathologic comparee de V inflammation, a book which 
contributed to the acceptation of the phagocyte 
theory and which showed the importance of Natural 
History applied to Medicine. 


Cholera Experiments on himself and others Illness of M. Jupille 
Death of an epileptic subject Insufficient results. 

THE acute period of the struggle in defence of the 
phagocyte theory now seemed to have come to an 
end and MetchnikofE turned his thoughts towards a 
new field of ideas. 

Having elucidated the essence of inflammation, 
he wished to study the origin of another pathological 
symptom, i.e. the rise in temperature which consti- 
tutes a feverish condition. To that end he undertook a 
succession of experiments on cold-blooded animals ; he 
injected microbes into crocodiles and serpents, hoping 
thus to provoke a rise in their temperature. But 
those experiments did not give the results expected. 

In the meanwhile (1892) cholera had made its 
appearance in France ; the specificity of the cholera 
vibrio was not finally established at that time. The 
observations made by Pettenkoffer on the immunity 
of certain regions, despite the presence of the cholera 
vibrio in the water, and the experiments made upon 
himself by that scientist, seemed to plead against the 
specificity of the cholera vibrio ; but other facts spoke 
in its favour. Desirous of solving this question, 
MetchnikofE went to a cholera centre in Brittany 
in order to fetch the necessary materials. Having 
done so, he attempted to produce cholera in divers 
kinds of animals, but without success. 



As he failed to solve the problem of the specificity 
of the cholera vibrio on animals, he resolved to experi- 
ment upon himself and consumed a culture of cholera 
vibriones. He did not contract cholera, which made 
him doubt the specificity of the vibrio, and therefore 
he consented to repeat the experiment on one of his 
workers (M. Latapie) who offered to submit to it : 
the result was the same. He then did not hesitate 
to accept the offer of a second volunteer (M. Jupille). 
The preceding results having led him to suppose that 
the cholera vibrio became attenuated in vitro and 
might perhaps serve as a vaccine against cholera, he 
gave a culture of long standing to the young volunteer. 

To his astonishment and despair, Jupille began 
to manifest the typical symptoms of cholera, and a 
doctor who was particularly conversant with the 
clinical chart of the disease declared the case a 
severe one because of the nervous symptoms which 
accompanied it. 

Metchnikoff was in mortal anxiety, and even said 
to himself that he could not survive a fatal issue. 
Fortunately the patient recovered, and this terrifying 
experiment proved indisputably the specificity of the 
cholera vibrio. Yet the irregularity of its action 
showed that in certain cases conditions existed which 
prevented the inception of the disease, and Metchni- 
koff supposed that this might be due to the action of 
the different intestinal micro-organisms. 

In order to simplify the question, he began by 
making experiments outside the organism. He sowed 
the cholera vibrio with divers other microbes and 
saw that some of them facilitated its culture whilst 
others prevented it. Similar experiments within the 
organism of animals gave no conclusive results ; the 


simultaneous ingestion of the cholera vibrio and of 
favourable microbes did not induce cholera. 

The flora of the intestines, complex as it is, probably 
played a part on which it was difficult to throw any 
light. Yet Metchnikoff did not give up the idea of 
producing a vaccine against this disease with attenu- 
ated microbes, or, if not, to prevent its inception by 
preventive microbes. His thesis was strengthened 
when one of his pupils, Dr. Sanarelli, discovered a 
series of choleriform bacilli in the absence of any 
cholera epidemic, one of those microbes being found 
at Versailles, a town which had remained immune 
during every cholera epidemic. 

Metchnikofi thought that this microbe, or some 
choleriform bacillus, similar though not specific, prob- 
ably served as a natural vaccine against cholera in those 
localities which were spared by the epidemic though 
the cholera vibrio was brought there. This was a 
question that could only be solved by experiment. 

At the time when he had himself absorbed a 
cholera culture, Metchnikofi admitted the risk of 
catching the disease ; still, his eagerness to solve the 
problem had silenced in him all other considerations 
and feelings opposed to his irresistible desire to attempt 
the experiment. This " psychosis," as he himself 
called it later, recurred now, in spite of all the emotions 
he had gone through on the previous occasion, and he 
decided once again to experiment on man. It is true 
that he now only had to deal with choleriform microbes 
from Versailles which he believed to be quite harm- 
less as they came from the water of a locality free 
from cholera. He therefore ingested some of the 
Versailles choleriform vibriones and gave some to 
several other people. Contrary to expectation, one 


of the latter, an incurable epileptic, showed some 
symptoms of cholera, but recovered. But as, a 
short time later, this patient died from a cause 
which remained obscure, Metchnikofi thought that 
possibly the experiment might have had something 
to do with it, and finally resolved to perform no 
other experiments on human beings. 

How could that unforeseen result be explained ? 
Metchnikofi supposed that the intestine of the subject 
contained favourable microbes which had exalted the 
virulence of the bacillus, in itself weak and innocuous. 
If it were so, then certain intestinal microbes would 
influence the inception of diseases and the action of 
the micro-organisms would vary according to the 
society in which they found themselves. As such 
problems could only be solved through experiment, 
he again energetically sought for a means of con- 
ferring cholera upon animals. After many failures 
and difficulties, it occurred to him to try new-born 
animals whose intestinal flora, not yet developed, 
could not interfere with the swarming of the ingested 
bacilli. He chose young suckling rabbits for his 
experiments and, with the aid of favourable microbes, 
he succeeded at last in giving them characteristic 
cholera, through ingestion ; thus it became possible 
to study intestinal cholera on these animals. 

However, numerous researches on the prevention 
of cholera by means of divers microbes gave no results 
sufficiently conclusive to permit their application 
to human beings. The problem was rendered ex- 
tremely complicated and difficult by the many and 
varied influences of numerous intestinal microbes and 
the inconstancy of microbian species in the same 


Pfeiffer's experiments, 1895 The Buda-Pest Congress Extracellular 
destruction of microbes Reaction of the organism against toxins 
Dr. Besredka's researches Macrophages The Moscow Con- 
gress, 1897 Bordet's experiments. 

METCHNIKOFF had scarcely recovered from all the 
emotions caused by his experiments on cholera, which 
he was still studying, when, in 1894, a work appeared 
by a well-known German scientist, Pfeiffer, bringing 
out new facts in favour of the extracellular destruc- 
tion of microbes. 

Whilst studying the influence of the blood serum 
within the organism and not outside it as his pre- 
decessors had done, he had found that cholera 
vibriones, injected into the peritoneum of a guinea- 
pig vaccinated against cholera, were nearly all killed 
in a few minutes and that they then presented the 
form of motionless granules in the peritoneal liquid. 
This granular degenescence, said Pfeiffer, took place 
apart from the phagocytes and therefore without 
their intervention. Metchnikoff repeated the experi- 
ment at once and ascertained that it was perfectly 

The complexity of biological phenomena being 
very great, he fully admitted the possibility of other 
means of defence in the organism besides that of 
the phagocytic reaction. However, this new fact 
disagreed so much with his own observation, and 



seemed so isolated, that Metchnikofi supposed an 
error of interpretation must have been made and 
tried to throw light upon it. He spent sleepless 
nights seeking the conclusive experiment which might 
explain Pfeiffer's phenomenon. 

His excitement was all the greater that he was 
very soon going to the International Congress at 
Buda-Pest, where he intended to expose the results 
of his new researches, and he feared that he should 
not have time to make all the experiments which he 
required in support of his arguments. However, the 
general impression of the Congress was clearly favour- 
able to the phagocyte theory. This is how M. Roux 
picturesquely described the scene at MetchnikofE's 
Jubilee in 1915 : 

" I can see you now at the Buda-Pest Congress in 1894, 
disputing with your antagonists ; with your fiery face, 
sparkling eyes, and dishevelled hair, you looked like the 
Daemon of Science, but your words, your irresistible arguments 
raised the applause of your audience. 

" The new facts, which had at first sight seemed to contra- 
dict the phagocyte theory, now entered into harmony with it. 
It was found to be sufficiently comprehensive to reconcile the 
holders of the humoral theory with the partisans of the 
cellular theory." 

This is how Metchnikoff had reconciled the apparent 
disagreement of Pfeiffer's phenomenon with the 
phagocyte doctrine : he demonstrated, by a series of 
experiments, that the extracellular destruction of the 
cholera vibriones in the peritoneum of a guinea-pig 
vaccinated against cholera, did in no wise depend on 
the chemical properties of the blood serum, but was 
simply due to the digestive juices which had escaped 
from the inside of the leucocytes, damaged by the 


intraperitoneal injection. Those digestive juices, or 
cytases, poured into the peritoneal liquid were what 
killed the injected cholera vibriones and transformed 
them into " PfeifEer's granulations." On the other 
hand, if by means of various precautions the phago- 
cytes were left unmolested, the extracellular destruc- 
tion did not take place and the vibriones were digested 
within the phagocytes. 

Metchnikoff used other experiments to prove that 
the bactericidal property of blood juices did not exist 
without intervention from the phagocytes. For 
instance, in a guinea-pig vaccinated against cholera, 
the bacilli are not destroyed if they are injected into 
parts of the organism that are devoid of pre-existing 
phagocytes, such as in the subcutaneous tissue, in 
the anterior chamber of the eye or in an aseptically- 
obtained oedema. On the other hand, if, in the same 
medium, some exudate is injected containing damaged 
leucocytes from which the digestive juice is leaking, 
the vibriones introduced are destroyed. The same 
results are obtained in vitro. 

All these experiments proved that the extra- 
cellular destruction of the cholera vibrio was accom- 
plished by the digestive juices which had passed from 
the phagocytes into the humors and not at all through 
a special property of those humors. Once again the 
phagocyte theory rose triumphant from the test. 

After having finally proved that it is by means of 
its phagocytes that the organism fights microbes, 
Metchnikofi wished to find out whether it was by 
the same process that it struggled with their poisons, 
or toxins. This problem, far more difficult to solve, 
took him many years' study. Whilst every phase 
of the phagocytes' struggle against microbes can be 


followed with the eyes, it is impossible to do so where 
poisons are concerned, since they are invisible ; it 
is necessary to proceed by a different road. 

Faithful to his method of taking as a starting-point 
the simplest expression of the phenomenon to be 
studied, Metchnikoff began by lower beings. Uni- 
cellular organisms, such as myxomycetes, amoebae, 
and infusoria, sometimes manifest a natural immunity 
to certain poisons. It is also possible to endow 
them with artificial immunity by accustoming them 
gradually to substances which, ingested straight away, 
would infallibly have killed them. Such phenomena, 
seen in unicellular beings, could only be ascribed to 
the reaction of the cell itself. Therefore Metchni- 
koff supposed a priori that the phagocytes, being 
similar primitive cells of multicellular beings, would 
also react against poisons. And, in fact, he ascer- 
tained that the number of phagocytes in a rabbit's 
blood diminished considerably under the influence of 
a fatal dose of arsenic, whilst it increased under the 
influence of small doses of the poison, to which it was 
possible to accustom the animal. 

Dr. Besredka, a disciple of Metchnikoff, made some 
very interesting researches, which entirely confirmed 
the share of the phagocytes in the reaction against 
sulphides of arsenic. He had chosen the trisulphide, 
a very slightly soluble salt of an orange colour, in 
order to find it again easily within the organism. 
After having injected non-fatal doses of it into the 
peritoneal cavity, he obtained an exudate in which 
all the orange granules of the salt were to be found 
included within those leucocytes which have a large, 
non-lobed nucleus the macrophages. These cells 
gradually digested the salt they had englobed, which 



ended by disappearing entirely within them, and the 
rabbit remained safe and sound. On the other hand, 
it died if the same doses of the same salt had been 
protected from the leucocytes by an elderberry bag, 
or when the leucocytes had been attracted elsewhere 
by a previous injection of carmine for instance. 
Those experiments removed all doubts as to the 
share of the phagocytes in the destruction of mineral 

Certain experiments on microbian poisons spoke 
in the same sense. Thus MM. Roux and Borrel had 
observed that the diphtheritic toxin, which is in- 
offensive to rats even in large doses, kills that animal 
if a small quantity of it is introduced into the brain, 
the probable explanation being that, in cases of sub- 
cutaneous injections, the poison, "phagocyted" on the 
way, was destroyed before it reached the nerve cells. 

Thus experiments seemed to plead in favour of 
the view that the part played by phagocytosis is not 
limited to the struggle against microbes, but also 
extends to the defence against poisons and toxins. 

After having studied the mode of destruction of 
these, Metchnikoff wished to elucidate the origin of 
the counter-poisons, the specific antitoxins discovered 
by Behring in the humors of immunised organisms, 
a question of which the study was even more difficult. 

Metchnikoff began by asking himself whether the 
microbes themselves did not produce antitoxins in 
order to defend themselves against enemy micro- 
organisms. He made many experiments but only 
obtained negative results, and concluded that the 
antitoxins must be manufactured by the organism 


The origin of this property must be more recent 
than that of the phagocytic reaction, for it does not 
exist in plants or in inferior animals. It was only 
from superior cold-blooded vertebrates, such as the 
crocodile and that only in artificial conditions and 
upwards, that Metchnikoff succeeded in rinding a 
specific antitoxic power in the humors. 

He ascertained that the vaccination of animals by 
toxins conferred, after a time, antitoxic powers to the 
blood and humors which contained leucocytes. He 
concluded therefrom that the presence of antitoxins 
depended on that of the phagocytes. Experiments on 
divers higher animals having proved that, in them 
also, antitoxins were localised in humors containing 
phagocytes, Metchnikoff concluded that the antitoxins 
were manufactured by the cells themselves. As 
toxins are absorbed and digested chiefly by macro- 
phages, it is probable that it is the latter also which 
manufacture specific antitoxins, or the final product 
of the digestion of corresponding toxins. Metchni- 
kofl could only propound this idea as an hypothesis, 
for the complexity and difficulty of a material demon- 
stration did not yet allow of a definite solution of the 
problem. However, certain observations on toxins 
and antitoxins pleaded in favour of this thesis. 

For instance, working in collaboration with MM. 
Roux and Salimbeni, he had found that it is by 
soluble poisons that the cholera vibrions harm the 
organism or kill it, but that small doses of the same 
poisons are vaccines and make the blood of the vac- 
cinated animal antitoxic. On the other hand, a 
microbian vaccination is preventive against microbes 
only but not against toxins and the blood does not 
become antitoxic. This is explained by the fact that 


it is not the same cells which digest cholera microbes 
and cholera toxins : the microphages digest the 
vibriones whilst the macrophages digest the poisons 
and, probably, manufacture as products of this 
digestion, the corresponding antibody, the cholera 

On the contrary, in cases of the inclusion of 
microbes by macrophages, as, for instance, in plague, 
the blood acquires an antitoxic power by injection of 
the microbes themselves and not by their toxins, as 
was demonstrated by M. Koux and his collaborators. 
The same fact was observed by Metchnikoff on the 
alligator, in whom also microbes are digested by 
macrophages. In those cases, when microbes and toxins 
are digested by the same cells, the latter manufacture 
antibodies against both. 

These facts rendered legitimate the supposition 
of the macrophagic origin of antitoxins. 

In 1897 an International Congress took place in 
Moscow. Metchnikoff read a paper on the phago- 
cytic reaction against toxins and another dealing 
with the whole of the knowledge acquired concerning 
human plague. He ended this by a plea in favour of 
Science, so often accused of having contributed 
nothing to the solution of the most important human 
problems, particularly ethical ones, and of having, 
on the contrary, sanctioned the law of Might by 
tabulating the laws of the struggle for existence. 
Metchnikoff objected that, far from doing so, Science, 
by revealing the laws of Nature, applied to humanity 
the benefits derived from them, whilst striving to 
counterbalance their cruel or harmful effects. The 
struggle against plague and other diseases was a 


concrete example of this, for here medical science 
opposed itself to the cruelty of " natural selection." 
He wound up his speech by the following words, 
" Just as, in order to satisfy his sesthetic tastes, 
Man revolts against the laws of Nature which creates 
races of sterile and fragile flowers, he does not hesitate 
to defend the weak against the laws of natural 
selection. Science has been faithful to her mission 
and to her generous traditions. Let her, then, progress 

Metchnikoff's friend and companion, M. Nocard, 
wrote to me concerning Metchnikoff's paper : 

Do not believe a word that MetchnikofE tells you. He 
had tremendous success. The somewhat free form of his 
paper contributed to its success, as it only made his conviction 
and enthusiasm more apparent. Thus the Sibyl on her 

Metchnikoff had at this period a very talented 
disciple, M. I. Bordet, who opened a new path by 
a series of researches of the greatest importance. 
He found, among other things, that " the figured 
elements " can be destroyed outside the cells, in the 
humors. Thus, if red blood corpuscles from one animal 
are injected into an animal of a different kind, these 
globules are destroyed, not within the phagocytes, 
but outside them, in the ambient humors. Metchni- 
koff studied this phenomenon and proved that the ex- 
planation was the same that he had previously given of 
Pfeiffer's phenomenon in the case of cholera vibrions. 
In Bordet's experiments, the leucocytes which were 
already existing in the humors were also damaged by 
the experimental shock ; but, if this was carefully 
avoided, the phagocytes, remaining intact, englobed 


and digested the injected red corpuscles and no 
phenomenon similar to Pfeiffer's took place. 

These observations led Metchnikoff to a thorough 
study of the destruction of cellular elements by the 
phagocytes. He had already observed that, whilst the 
struggle with microbes is chiefly undertaken by small 
leucocytes with a lobed nucleus the microphages 
it is the great leucocytes with a single large nucleus 
the so-called macrophages which undertake the 
destruction of cells, "figured" elements, as well as that 
of toxins. The macrophages are to be found not only 
in the blood but also in different organs such as the 
liver, spleen, kidneys, etc. ; they seize upon living 
cells by means of mobile protoplasmic prolongations 
with which they draw them in and end by ingesting 
them completely. Not only do they thus absorb 
foreign cellular elements such as red corpuscles, 
spermatozoa, etc., but also all the weakened cells 
of the organism itself. 

This weakening may be due to normal phenomena 
such as the metamorphosis of insects or tadpoles, 
when certain organs, as they weaken, become useless 
or inactive. But, oftener, this weakening is due to 
pathological causes, as in morbid atrophies or poisoning 
by microbian toxins. In any case, the enfeeblement 
of cells exposes them to be devoured by macro- 
phages, which brings about the atrophy of the cells 
or even of the organs which contain them. 

These observations suggested to Metchnikoff the 
idea that senile atrophy might be due to the same 
mechanism, and his thoughts turned towards the 
problem of the causes of old age. 

But, before undertaking researches in a new 
direction, he wished to conclude those he had been 


pursuing for twenty years on the phenomenon of 
phagocytosis. He therefore started to complete his 
investigations on immunity in order to epitomise 
them and to give a definite form to his doctrine on 
that subject. 


1900. Immunity Natural Immunity Artificial Immunity. 

FOR centuries the question of immunity has occupied 
the human mind because the prevention of disease 
has ever been one of the greatest preoccupations of 
Man. Savages had already observed that man can 
become refractory to the venom of serpents, either 
through a slight bite or by the application of certain 
preparations of that venom on scarified skin. It 
was also a popular and very ancient notion that the 
contact of a slightly scratched hand with the pustules 
of cow-pox conferred immunity against human small- 
pox. It was on this observation that Jenner founded 
his method of antivariolic vaccination. The latter, 
in its turn, suggested to Pasteur the idea of attempting 
antimicrobian vaccinations. Having ascertained that 
old cultures of chicken cholera, previously very viru- 
lent, had become harmless, he wondered whether they 
had become a vaccine and proved by experiment 
that they had. That led him to the principle of the 
attenuation of viruses and to that of vaccination 
by attenuated microbes. Thus the problem of the 
mechanism of immunity was stated. 

The first theories propounded on the subject con- 
cerned the humors. Pasteur supposed that im- 
munity was due to the absorption, by the vaccinating 
microbes, of certain nutritive substances in the humors, 



which, not being renewed for some time, were missed 
by the microbes afterwards introduced into the organ- 
ism, which therefore could not develop completely. 
Chauveau, on the other hand, thought that, in cases 
of immunity, the humors contained substances which 
were unfavourable to microbes. Those theories ex- 
plained particular facts, but were not applicable to 
the generality of cases. 

Other theories, 1 whilst attributing an active part 
to the organism itself, failed to account for the 
mechanism of immunity in general. This was due 
to the fact that knowledge at that time lacked the 
two essential elements, i.e. the modifications suffered 
by the organism which was becoming immunised, and 
the fate of the microbes in the refractory organism. 

The disappearance of the microbes in the cured 
or refractory animal had indeed been observed ; 2 the 
inflammatory reaction of the organism in the course 
of immunisation had been noted ; 3 microbes had 
long ago been observed inside the white globules of 
pus ; 4 but, either an erroneous interpretation was 
given to the facts observed, or, rather, the links of 
causality between those factors failed to be established 
because they were observed solely in the complicated 
organism of superior beings. Humoral theories, less 
easy to test, preserved an appearance of generality 
and were easily admitted. 

Such was the state of the question when Metchni- 
koff approached it from a naturalist's point of view. 
He knew the life of unicellular beings and that of the 
lower multicellular organisms in their complete sim- 

1 Naegeli, Biichner, Gravitz. 2 Chauveau. 

3 Biichner. 

4 Hayem, Birach, Hirschfeld, Kleps, Recklinghausen, Waldeyer, and 


plicity ; he knew their mode of defence by ingestion 
and intracellular digestion. Having become familiar 
with these phenomena, visible in the single cell, he 
was better able to see his way in the complicated 
milieu of higher beings. He was therefore able to 
discover the connection between the divers factors 
which other scientists had observed singly. He was 
able to prove that it is the combination of these 
factors, i.e. inflammation, the ingestion of living and 
virulent microbes, and their disappearance by means 
of intracellular digestion which makes immunity 
possible. He demonstrated that " there is but one 
permanent element in natural or acquired immunity, 
and that is phagocytosis." 

The extension and importance of this factor, 
applicable to the whole animal kingdom, proved the 
truth and general scope of the phagocyte doctrine 
of immunity. 

In 1900, Metchnikoff presented to the Inter- 
national Congress in Paris a complete tabulation of 
his researches and fought his contradictors for the 
last time, after which, convinced that his deductions 
were solid, he began to write a work on Immunity in 
Infectious Diseases. In it he epitomised, as in a great 
harmonious chord, the results of his researches, reach- 
ing over a period of nearly twenty years ; he affirmed 
and gave final expression to his doctrine of immunity, 
based on the comparative study of the mechanism of 
that phenomenon and of its evolution along the whole 
scale of living beings ; he related his controversies, 
analysed the objections to his doctrine, expounded 
the theories of other scientists concerning immunity, 
and gave a general view of the present state of 
the question. This book is a living picture of a 


long and important part of MetchnikofTs scientific 

The question of immunity is of such great im- 
portance, the mechanism of this phenomenon and 
the physiology of intracellular digestion are so com- 
plicated, that I have thought it useful to epitomise 
here the exposition given of it by Metchnikoff in his 
book. Readers who do not care to go further into 
the subject can pass over the next few pages with- 
out hindering their comprehension of the following 

Diseases affect all living beings, and the greater 
number of plants and animals would cease to exist 
without innate or acquired immunity. 

Unicellular beings are generally immune against 
infectious diseases, which are rarely observed in them. 
Their body being almost entirely made up of digestive 
protoplasm, the microbes which they absorb are 
directly introduced into a noxious medium and are 
destroyed therein like any other food. If the 
microbes are indigestible, they are immediately 
rejected ; hence, in the majority of cases, they 
cannot become harmful. 

This resistance of unicellular beings to many 
microbes and microbian toxins is due not only to 
the intense digestive power of the cell but also to 
the extreme sensitiveness which rules over the choice 
of food. Owing to this protoplasmic sensitiveness 
(chimiotaxis) protozoa are attracted towards certain 
microbes or substances (positive chimiotaxis) and re- 
pelled by others (negative chimiotaxis). Thus, many 
ciliate infusoria choose bacteria only for their food ; 
they are sharply repelled by dead infusoria, etc. 


Therefore, in the natural immunity of unicellular 
beings, two fundamental elements may already be 
observed : sensitiveness and intracellular digestion. 
No researches have yet been made on the possibility of 
conferring on protozoa an artificial immunity against 
certain pathogenic microbes and their poisons. But 
unicellular beings, insensible to microbian poisons, are 
the reverse to many chemical substances which, in their 
normal life, they have no opportunity of ingesting. 

It has been proved by experiment that, against 
many of those chemical substances, an artificial im- 
munity may be given to the protozoa by accustoming 
them gradually. Very diluted solutions are added at 
first to the medium in which they live and, by gradu- 
ally concentrating those solutions, an artificial im- 
munity is conferred ; the negative chimiotaxis becomes 
positive, allowing the protozoa to absorb and digest 
the poison, now become a food. 

Habit is therefore the fundamental condition of 
artificial immunity ; it must be that also of immunity 
naturally acquired. Having accidentally digested 
enfeebled microbes or having suffered an attack of 
disease, the unicellular being becomes accustomed to 
a stronger virus and becomes immune against it. 
The fact that so many unicellular beings have become 
thus accustomed is therefore connected with their 
sensitiveness and their digestion. Accordingly, 
sensitiveness, habit, and digestion are the funda- 
mental factors of the mechanism of immunity in 
protozoa ; this immunity thus indisputably belongs 
to the category of purely cellular phenomena. 

Having arrived at this conclusion, Metchnikoff 
thought that the same mechanism of immunity must 
be found in other primitive and analogous cells, such 


as the phagocytes of multicellular beings. This was 
proved by a whole series of observations and by the 
fact that the immunity of higher animals is connected 
with an intense phagocytosis. In fact, as he ascended 
the scale of beings and studied their natural and 
artificial immunity, he ascertained that, in all of them, 
the essence of immunity, masked by the complexity 
of the organism, reduced itself to the phagocytes 
becoming accustomed to noxious agents. The mechan- 
ism of immunity in protozoa could therefore really be 
compared with that of immunity in multicellular 

Becoming accustomed and becoming immune are 
phenomena of a general order, for they can be mani- 
fested not only by animals, but also by plants. They, 
too, have to defend themselves against numerous 
diseases. Lower vegetables, such as myxomycetes 
(beings which stand on the limit between the animal 
and vegetable kingdoms), have an amo3boid phase, 
in which they are but a simple heap of formless 
protoplasm. During that stage of their life, myxo- 
mycete behave towards noxious agents exactly in 
the same way as unicellular beings and, like them, 
acquire immunity by becoming gradually accustomed. 

In higher vegetables, the mechanism is different 
because of their structure. The cells of nearly all 
plants are immobilised by rigid membranes ; there- 
fore they cannot surround their prey, but protect 
themselves by the production of tough membranes 
(cicatrisation) and by the secretion of various juices. 
Certain of these juices (gums and resins) become 
solid when exposed to the air and constitute a sort 
of natural (dressing) ; others (essences) are antiseptic. 
The secretion of these cellular juices in plants is 


therefore a powerful means of defence. This defence 
is due to the extreme sensitiveness of the protoplasma 
of vegetable cells : they react against irritation by a 
defensive secretion. Vegetables, as well as unicellular 
beings, can accustom themselves or become artificially 
accustomed to noxious influences and acquire im- 

As to animals, Metchnikoff had already proved 
long ago that they defend themselves against morbid 
agents by phagocytosis, i.e. by intracellular digestion. 
It is always to be found in cases of immunity and is 
indispensable to it, on the same grounds as in uni- 
cellular beings. The organism of multicellular animals 
possesses various cells which play the part of phago- 
cytes. There are some in the blood and humors, as 
also in the divers organs and in the tissues. These 
phagocytes are either mobile leucocytes, or fixed 
tissue-cells. However, all those cells may be classed 
into two principal groups : the microphages and the 
macrophages. Both categories of cells are capable of 
digesting microbes, but it is chiefly done by the micro- 
phages, whilst macrophages more especially digest 
figured elements (cells) of animal origin and poisons. 
It may be said that the microphages are vegetarians 
whilst the macrophages are chiefly carnivorous. 

What, then, is the mechanism of phagocytic 
digestion ? 

Intracellular digestion by phagocytes is accom- 
plished by means of digestive ferments, similar to 
those of our own digestive organs. " In both cases," 
says Metchnikoff, " a diastasic action is due to soluble 
ferments produced by living elements. In intra- 
cellular digestion, the diastases digest within the 
cells, whereas in extracellular digestion the pheno- 


menon takes place outside the cells, in the cavity of 
the gastro-intestinal tube." 

Only gradually has intracellular digestion given 
place to the digestion by secreted juices. The link 
between these two modes is to be found in certain 
transparent Invertebrates, such as the floating mol- 
lusc Phyllirhoe. The nourishment is first digested 
in the cavity of the digestive tube by secreted juices, 
and its treatment is completed within the amoeboid 
cells of the caecum. 

In higher animals, the digestion of food is due 
to several digestive ferments (rennet, pepsin, tryp- 
sin, enterokinase, etc.) produced by divers organs 
(stomach, pancreas, intestines). The phagocytes 
also manufacture several digestive ferments; their 
principal digestive juice is a soluble ferment of the 
trypsin category, to which Metchnikoff gave the 
name of cytase. 1 

To the morphological difference of the phagocytes 
corresponds also a difference in the properties of their 
cytases, which are suited to the digestion of this or 
that food. The cytases are kept within the interior 
of the cells and only escape into the humors when 
the phagocytes are damaged (Pfeiffer's phenomenon). 
This kind of ferment does not withstand a tempera- 
ture above 55 to 58 C. In natural immunity, it 
plays the principal part by digesting morbid agents 
inside the phagocytes like any other food. But, in 
artificial immunity., other soluble ferments come into 
play, developed in consequence of vaccination. 

The principal of those is the fixator. 2 It is less 

1 It ia also called alexine or complement by other writers. 

2 Designated by other writers by various synonyms : preventive, or 
sensibilising substance, immunising body, amboceptor. 


sensitive than cytasis to high temperatures and can 
bear a temperature of 65 to 68 C. It is incapable, 
by itself, of killing and digesting, but by fixing on 
them, it bites them, so to speak, and makes them 
sensitive to the action of the phagocytic cytases, 
which can thus digest them more easily. 

The fixator may be compared to enterokinase, a 
special ferment in the small intestine of higher animals 
which also does not by itself digest food but which 
activates in a high degree the digestive power of 
pancreatic ferments. However, it has the property 
of fixing itself on fibrin ; it is obvious that entero- 
kinase and the fixator have the same essential 
properties. This similarity again proves that the 
destruction of morbid agents by the phagocytes 
really corresponds with actual digestion. 

It is in consequence of the digestion of vaccinal 
products that the phagocytes manufacture the fixator. 
Created at the expense of a given vaccinal substance, 
the fixator has a specific character which corresponds 
with that substance, whereas the cytase already 
existing within the phagocytes never has a specific 

Artificial immunisation generally produces the 
formation of so great a quantity of fixators that the 
phagocytes are unable to retain them and excrete them 
in part in the ambient humors, i.e. the blood plasma, 
or serum. When, afterwards, virulent morbid agents 
(microbes or figured elements) are introduced into 
an organism which has been immunised against them, 
they are at once faced, in the humors, with fixators, 
which immediately exert a biting action on them 
and render them sensitive to the action of the 
intracellular cytasis of the phagocytes. The same 


mechanism explains the specificity of the serums of 
vaccinated animals. 

The quantity of specific fixators in the humors 
depends on the surplus production of that ferment by 
the phagocytes and is not always the same. That is 
why different serums are preventive in different 
degrees. They are inactive if the phagocytes have 
not produced enough fixators to pass any out into 
the humors. For a serum is only preventive when it 
brings into the new organism into which it is in- 
jected a sufficient quantity of fixators ready to 
sensibilise the morbid agents afterwards introduced 
into the organism. 

The over-production of antibodies fixators or anti- 
toxins corresponds up to a certain point with the 
frequency and quantity of vaccinal injections ; that 
is why serums are usually preventive in artificial 
immunity and very rarely so in natural immunity. 
Through successive inoculations, the cells become 
accustomed to digesting the microbes, or figured 
elements, and manufacture, in consequence of that 
digestion, growing quantities of fixators. 

In natural conditions, on the other hand, morbid 
agents do not usually penetrate into the organism in 
massive or repeated doses ; therefore digestion under 
natural conditions results in a less abundant produc- 
tion of fixators which can be contained in the interior 
of the phagocytes without leaking into the humors 
in sufficient quantities to render the latter preventive. 

It might be thought that immunity against patho- 
genic microbes is accompanied by immunity against 
their toxins. In reality that is not always the case, 
and very often the organism, now made refractory 
to certain microbes, remains sensitive to their toxic 



products. Thus antimicrobian immunity and anti- 
toxic immunity constitute in most cases two distinct 
properties. In order to confer antitoxic immunity 
recourse must be had to vaccination by soluble poisons 
and toxins. 

Immunity, acquired naturally, is so especially 
against microbes and not against toxins, for, in nature, 
it is almost always by microbes that the organism 
is threatened. As to antitoxic immunity, it is very 
probably due to the intracellular digestion of toxins 
by the different macrophages. This hypothesis is 
supported by the experiments quoted in the pre- 
ceding chapter. During antitoxic vaccination, the 
macrophages manufacture, probably at the expense 
of vaccinal toxins, a certain quantity of antitoxins, 
substances which offer a great similarity with the 
fixators. Like them, they are specific ; they are 
also produced in great quantities and excreted into 
the humors, which they render antitoxic when suffi- 
ciently abundant ; finally, they are not very sensitive 
to high temperatures. That is why, in spite of the 
impossibility of proving their origin directly, it is 
quite probable that it is analogous to that of the 
fixators and that antitoxins are manufactured by 
cellular elements, the macrophages in particular. For 
it is they which absorb and digest toxins as well as 
soluble poisons. 

This deduction is also supported by the antitoxic 
immunity which may be conferred on unicellular 
beings in which the cell alone enters into play. 

Phagocytes no doubt manufacture many other 
soluble ferments corresponding with the elements 
which they absorb, for, in a vaccinated organism, 
divers new specific properties of the serum are to be 


found, such as that of agglutination, precipitation, etc. 
Humoral properties may be more or less durable, 
in proportion as the products manufactured by the 
phagocytes are more or less rapidly evacuated by the 

All these humoral properties, traced back to their 
first source, depend upon the digestive activity of the 
phagocytes, since they are the products of that 
digestion. In cases where it has not yet been possible 
to make a direct demonstration of this, it becomes 
evident through analogy and experiments pointing in 
that direction. 

To sum up, according to Metchnikoff, " Immunity in 
infectious diseases is linked with cellular physiology, 
namely, with the phenomenon of the resorption of 
morbid agents through intracellular digestion. In a final 
analysis, the latter (as also the digestion of food in 
the gastro-intestinal tube) reduces itself to phenomena 
of a physico-chemical order ; however, it is a real 
digestion accomplished by the living cell. . . . The 
study of Immunity, from a general point of view, 
belongs to the subject of Digestion." 

Immunity against diseases is but one of the mani- 
festations of an immunity on a much larger scale, 
always based, in final analysis, on the sensitiveness 
of the living cellular protoplasm. The sensitiveness 
of the nervous cells extends this phenomenon to 
the psychical domain. They also are capable of 
becoming accustomed to external irritations of all 
kinds, hence constituting a psychical immunity for 
the organism. We all know that one can become 
accustomed to many painful or violent sensations; 
and, as MetchnikoS says : "... It is very probable 
that the whole gamut of Habit, starting from the 


unicellular beings, who accustom themselves to live in 
an unsuitable medium, to cultured men who acquire 
the habit of not believing in human justice, rests on 
one and the same fundamental property of living 


Private sorrows Death of Pasteur, 1895 Ill-health Senile atrophies 
Premature death Orthobiosis Syphilis Acquisition of an- 
thropoid apes. 

METCHNIKOFF'S health had suffered from the numerous 
emotions provoked by the struggle in defence of the 
phagocyte doctrine and also from a series of sad 
events. In 1893, sickness and death fell upon our 
family ; I lost a sister and a brother at a short interval 
and had myself to undergo a serious operation. My 
husband nursed me night and day, as a mother might 
have done, and went through the deepest anxiety 
on account of post-operative complications. All this 
told on him all the more that he had just endured 
cruel moral suffering during the experiments on cholera 
mentioned above. In 1894, an agricultural crisis in 
Russia influenced our material situation and gave him 
many worries. In the autumn of 1895, M. Pasteur's 
health became worse and, soon afterwards, he died. 

This series of calamities depressed Metchnikoff, his 
old cardiac trouble returned, and he again became a 
prey to insomnia. We spent part of the holidays in 
the mountains, thinking it might do him good, but 
he did not care for a prolonged rest ; he was pre- 
occupied by the thought of his interrupted experiments 
and only thought of returning to the laboratory. 

In 1898, he had some disquieting symptoms of 



kidney trouble, a little albumen. He consulted the 
celebrated German physician, von Noorden, who 
found nothing serious, but this did not reassure him 
and he continued to worry about himself. 

Already some time previously, theoretical considera- 
tions on senile atrophies had directed his thoughts 
towards old age. His reflections now turned towards 
the psychological aspect of the problem ; he analysed 
his personal sensations and realised that he, at the 
age of 53, felt an ardent desire to live. This imperious 
instinct for life, in spite of the inevitable evolution 
towards personal death and old age, brought his 
thoughts back to the disharmonies of human nature. 
But now, through all his gloomy reflections, he was 
borne up by the unshakable conviction that Science 
would succeed in correcting those disharmonies and 
he continued to work with untiring energy. 

He had prescribed for himself a hygienic diet, 
based on the idea that the cause of his own condition 
and senility in general was due to a chronic poisoning 
by intestinal microbes. This diet consisted in avoiding 
raw food in order not to introduce noxious microbes 
into the intestines, and in absorbing their useful 
enemies, the acid-forming microbes of sour milk. 
This diet was very favourable to his health. 

After he had finished his book on immunity he at 
last allowed himself to pass on to the new questions 
which preoccupied him, i.e. senility and death. 

He set forth a sketch of his ideas in 1901 in a 
paper which he read at Manchester (Wilde Lecture) 
on the " Flora of the Human Body." He reviewed 
this flora and pointed out the harmful effect of the 
microbes, especially those of the large intestine the 
toxins of which effect a chronic poisoning of the 


cells of our organism and thus provoke their gradual 
weakening. He then indicated the means of combat- 
ing this evil, on the one hand by stimulating the vital 
activity of the cells exposed to enfeeblement, by 
means, for instance, of small doses of specific cyto- 
toxins, and, on the other hand, by direct action on 
intestinal microbes. He concluded by saying that 
" the intestinal flora is the principal cause of the 
too short duration of our life, which flickers out 
before having reached its goal. Human conscience 
has succeeded in making this injustice obvious ; 
Science must now set to work to correct it. It will 
succeed in doing so, and it is to be hoped that the 
opening century will witness the solution of this great 

Metchnikoff considered that our chronic poisoning 
by intestinal microbes weakens our cellular elements ; 
he supposed that the same cause might provoke 
senile phenomena, manifestly due to weakness of the 

One of the first manifestations of senility being the 
whitening of hair, he began to study the mechanism 
of that. He had previously observed the dominant 
part played by phagocytosis in all phenomena of 
atrophy, and it occurred to him that it may be phago- 
cytes which destroy the colouring matter of hair, a 
substance which, in the form of tiny granules, is 
enclosed within the hair cells. In fact, he found 
that the whitening process is accompanied by a 
stimulation of the amoeboid cells which introduce 
their protoplasmic prolongations into the periphery 
of the hair. They absorb the coloured granules, or 
pigment, and digest it, partly on the spot, partly 
after carrying it into the root of the hair, often even 


in the connective tissue which supports the hairy 
scalp. As the pigment becomes destroyed, the hair 
loses its colour and whitens. The cells which devour 
the pigment pigmentophages belong to the cate- 
gory of macrophages which, in general, absorb all the 
enfeebled cells in the organism. 

MetchnikofE was able to note similar phenomena 
in divers other senile atrophies either by his own 
ulterior researches or by collaboration with his pupils 
(MM. Salimbeni and Weinberg). 

In the same way that the whitening of the hair 
depends on the destruction of pigment by pigmento- 
phages, the wrinkles of the skin, weakness of the 
muscles, friability of the bones, and senile degeneres- 
cence of divers organs are caused by the destruction 
of weakened cells which do not defend themselves 
and thus become the prey of the stronger and more 
resisting macrophages. Senility is thus no other than 
a generalised atrophy. What is it that provokes it ? 
The answer is : The swarming microbes in our large 
intestine. They form the permanent source of a 
slow poisoning of our organism. This fact alone 
suffices to explain one of the principal causes of the 
enfeebling of our tissues. It is not simultaneous in 
all the cells because of their different powers of 
resistance. The struggle and destruction of the weak 
by the strong is the cruel law of nature ; therefore 
the macrophages, more resisting to poisons, take 
advantage of the weakening of other cells in order 
to devour them, and this is one of the causes of 

These reflections and the biological researches which 
confirmed them allowed Metchnikoif gradually to 
build up a philosophical doctrine, which he ex- 

pounded in 1903 in his work, fitudes sur la nature 

He considered " old age " as a pathological pheno- 
menon. He saw in it one of the most important dis- 
harmonies of human nature, because of the fact that 
neither senility nor death is accompanied by a natural 
instinct. The accomplishment of every physiological 
function leads to satiety or to a desire for rest ; after 
a busy day, man feels an instinctive need for rest and 
sleep. But, in his maturity, he has no desire to grow 
old, and in his old age none to die. It is rare that 
one should aspire to die, and nobody wishes to grow 
old. These facts are in contradiction with other 
natural phenomena ; they are all the more discordant 
that they play an immense part in our psychical life. 

After a general review of opinions on human nature, 
Metchnikoff analysed it from the biological point of 
view ; he revealed its discords and concluded that it 
is far from being perfect. In his eyes, the lack of 
harmony in the human being is an inheritance from 
our animal ancestors ; they have handed down to us 
a whole series of remains of organs which are not only 
useless but even harmful in the new conditions of 
human existence. 

The large intestine, inherited from mammalian 
ancestors, holds the first place among those noxious 
organs. This reservoir of food refuse was very useful 
to our animal forebears in their struggle for existence ; 
it allowed them not to interrupt their flight whilst 
pursued by their enemies. In man, whose life condi- 
tions are different, a large intestine of that size, 
without offering the same advantages, is a source of 
slow and continuous poisoning and a cause of prema- 
ture senility and death. 


Man, after acquiring a still higher development, 
realised these evils and made concentrated efforts to 
fighfc them and to soothe his own terrors. It is for 
that object that the divers religious and philosophical 
systems were created, in which humanity sought for 
consolation. Finding none there, man turned to 
Science, which, at first, neither solved his doubts nor 
eliminated his sufferings. But Science provided him 
with rational methods of research, owing to which he 
gradually progressed and conquered a series of truths, 
allowing him gradually to struggle against some of 
his troubles and to solve some of his problems. 
Science has already done much to diminish the diseases 
which are among the chief scourges of humanity. 
It has thrown light upon the causes of many of them 
and has found preventive and curative remedies for 

Surgery, antiseptics, serotherapy, vaccinations 
already yield secure results. Hygiene and prophy- 
laxis are in course of development, and a vast prospect 
is open to them in the future. But our heaviest 
burdens, senility and death, common to all, have yet 
scarcely been studied. Having expounded his views 
on senility and proved that it is a pathological pheno- 
menon, Metchnikoff concluded that to struggle against 
it was quite as possible as to struggle against disease. 

The principal causes which bring about premature 
senility are : alcoholism, chronic poisoning by intes- 
tinal microbes, and infectious diseases, headed by 
syphilis. Surely Science will discover efficacious 
means against all these. 

The strengthening of the beneficent cells in our 
organism ; the transformation of the wild intestinal 
flora into a cultivated flora, by the introduction of 


useful microbes ; the struggle against infectious 
diseases and alcoholism all these are workable means 
of fighting pathological and premature senility. 

When old age becomes physiological and no longer 
painful it will become proportionate with the other 
epochs of our lives and cease to alarm us. But how 
is the fear of death to be explained, since it is a general 
and inevitable phenomenon ? How is it that we have 
no natural instinct for death ? Metchnikoff supposes 
that this lack of harmony in our nature comes from 
the fact that death is as premature as senility and 
arrives before the natural instinct for it has had time 
to develop. This supposition is confirmed by the 
fact that old people who have reached an excep- 
tionally advanced age are often satiated with life 
and feel the need of death as we feel a need of sleep 
after a long day's work. That is why we have a 
right to suppose that, when the limit of life has been 
extended, owing to scientific progress, the instinct of 
death will have time to develop normally and will 
take the place of the fear which death provokes at 
the present day. Both death and old age will become 
physiological and the greatest discord in our nature 
will be conquered. 

Our manner of life will have to be modified and 
directed according to rational and scientific data if 
we are to run through the normal cycle of life ortho- 
biosis. The pursuit of that goal will even influence 
the basis of morals. Orthobiosis cannot be accessible 
to all until knowledge, rectitude, and solidarity 
increase among men, and until social conditions are 

Man will then no longer be content with his natural 
inheritance ; he will have to intervene actively in 


order to correct his disharmonies. "Even as he 
has modified the nature of plants and animals Man 
will have to modify his own nature in order to make 
it more harmonious." 

In order to obtain a new race, one forms an ideal 
in relation to the organism to be modified. " In 
order to modify human nature, it is necessary to 
realise what is the ideal in view, after which every 
resource of which Science disposes must be taxed in 
order to obtain that result. If an ideal is possible, 
capable of uniting men in a sort of religion of the 
future, it can only be based on scientific principles. 
And if it is true, as is so often affirmed, that it is im- 
possible to live without faith, that faith must be 
faith in the power of Science." 

In those words, Metchnikoff ends his book on 
Human Nature. 

The public at large and many critics did not under- 
stand the deep and general meaning of Metchnikoffs 
thoughts. They reproached him with having an in- 
sufficiently exalted ideal, for they only saw in his 
doctrine the desire of postponing senility and living 
longer. They did not understand that to revolt 
against the lack of harmony in nature, through which 
all humanity has to suffer, not only physically but 
morally, was to aspire to perfection. They did not 
consider that, in order to attain that end, all human 
culture and the whole social state would have to be 
modified ; that this could only be done through many 
virtues, intense energy, and great self-control. They 
had not understood the elevation and power of an 
ideal which aspired to perfect not only the direction 
of life but human nature itself. They had not under- 


stood the audacious beauty of such a struggle, the 
benefit conferred by the belief that the human will 
and the human mind are capable of transforming 
Evil into Good according to a conceived ideal ! . . . 

In the meanwhile Metchnikoff, convinced that 
Knowledge is Power and that " Science alone can 
lead suffering Humanity into the right path," quietly 
continued his task. 

One of the most characteristic symptoms of old 
age is the hardening of the arteries arterio-sclerosis. 
He therefore especially wished to elucidate the mechan- 
ism of that phenomenon. 

Whilst many, yet unknown, factors come into 
play in senility, one disease, syphilis, often provokes 
arterio-sclerosis, indisputably due to a morbid agent. 
Metchnikoff therefore began to study this disease, 
of which the origin is infectious especially as he 
thought he could do so experimentally. 

Long before this, he had conceived the idea that 
the study of those human diseases which cannot be 
transmitted to ordinary laboratory animals might be 
carried out on anthropoid apes, of all animals the 
nearest to man. He had spoken of it to M. Pasteur, 
but, at that time, the Institute could not afford to 
acquire these costly animals. In 1903, at the Madrid 
Congress, Metchnikoff received a 5000 fr. prize and 
utilised this money in the acquisition of two anthro- 
poid apes. The same year M. Roux won the Osiris 
prize of 100,000 fr. which he devoted to the same 
object, and it was decided that the two together 
would undertake researches on syphilis. Other dona- 
tions, 30,000 fr. from the Morosoffs of Moscow and 
250 roubles from the Society of Dermatology and 


Syphilography of the same city, completed the capital 
required to execute the projected plan. 

The following is a short sketch of the researches that 
were undertaken and the results that were obtained. 

The inoculation of anthropoid apes with syphilis 
was successful. The chimpanzee was found to be 
most sensitive to the disease ; it manifests primary 
and secondary symptoms identical with those of 
man. Lower monkeys, though less sensitive, also 
contract syphilis but generally only show primary 
characteristic manifestations. The possibility of 
rapidly provoking in apes, even of the inferior kinds, 
syphilitic lesions similar to those of man has a very 
great importance, for it provides a sure means of 
diagnosis in doubtful human cases. Owing to the 
liability of apes to contract syphilis, experimental 
vaccination and serotherapy could be attempted on 
them ; but, though these experiments were sometimes 
encouraging, the results obtained were not constant 
enough to justify their application to man. Thus, 
it was found possible to attenuate the virus by 
successive passages in certain lower apes, and yet, 
though attenuated for the chimpanzee, it did not 
confer upon him immunity against the active virus. 

In 1905, Schaudinn discovered the syphilitic tre- 
ponema in man. By using this discoverer's method, 
the same microbe was found in apes inoculated with 
human virus, which confirmed the specific character 
of the treponema. 

An observation was then made which was of great 
importance on account of its consequences : it was 
ascertained that the syphilitic microbe was absorbed 
by the less mobile mononuclear phagocytes and re- 
mained localised near the entrance point long enough 


to allow of a local treatment which might succeed 
in being curative as it had time to act before the 
microbes had passed into the general circulation of 
the organism. This supposition was proved to be 
correct by a series of experiments on monkeys, and, 
in 1906, a young doctor, M. Maisonneuve, inoculated 
himself with syphilis and applied the treatment with 
a perfectly satisfactory result. 

It might have been thought that this simple, safe, 
and innocuous method would at once come into prac- 
tice, but it was not so. Between opposition on the 
one hand, and carelessness of the subjects themselves 
on the other, this useful discovery remained for a long 
time without being utilised. All the above results were 
obtained through experiments on anthropoid apes, 
and the study of syphilis, until then purely clinical, 
entered at last into the field of experimental science. 

Researches upon syphilis were but an interlude ; 
Metchnikoff, returning to his principal work, resumed 
the study of senility and of the intestinal flora. 
During many years he applied himself to researches 
concerning the part played by the latter within the 

He was able to confirm the deductions expounded 
in his Etudes sur la nature humaine, and in 1907 he 
published a new work, Essais optimistes, in which he 
developed the same ideas, amplified by the results 
of his new researches, and answering the criticisms 
excited by his first book. 

In the Essais optimistes he studied first of all the 
phenomena of old age in the different grades of the 
scale of living beings, of which he compared the life 
duration. He concluded jjthat there was an indubit- 


able connection between this and the intestinal 

The shorter the intestine, the fewer microbes it 
contains and the longer the relative duration of life. 
As an example, he quoted the relatively great lon- 
gevity of birds and bats. Those animals, adapted to 
aerial life, have to weigh as little as possible. To 
that end, they empty their intestine very frequently 
and this in consequence is not used as a reservoir 
for alimentary refuse ; as it is but little developed, it 
contains a much smaller number of microbes. The 
longevity of flying animals is relatively much greater 
than that of mammals with a large intestine full of 
microbes, a constant source of slow poisoning. 

After treating the question of longevity, Metchni- 
kofi dealt with that of death. 

Living beings die, in the great majority of cases, 
in consequence of diseases or accidents with an 
external cause ; one involuntarily wonders whether 
there is such a thing as " natural death," i.e. arising 
exclusively from causes due to the organism itself. 
A review of known facts allowed MetchnikofE to draw 
the following conclusions : unicellular inferior beings 
have no natural death ; they merely die by accident. 
Their individual life is very short and comes to an 
end by multiplication or division of a unit into two ; 
there is no trace of a corpse in this loss of previous 

Among superior plants, certain trees attain con- 
siderable dimensions (dragon-tree, baobab, oak, 
cypress), live for centuries, and die from external 
causes. Their organism presents no internal necessity 
for a natural death. On the other hand, a multitude 
of other plants have but a short life and their natural 


death coincides usually with the ripening of the seed. 
It has even been observed that it is possible to 
retard the death of a plant by preventing it from 
fructifying. For instance, lawns made up of grass 
mown before it runs to seed remain green and living 
whilst grass allowed to flower and bear seed becomes 
yellow and dries up. It is a well-known fact that 
fruits and seeds are frequently poisonous. Therefore 
Metchnikoff supposed that the death of the plant may 
be due to an auto-intoxication by poisons manu- 
factured by it in order to defend its seeds and ensure 
the next generation ; in Nature, the individual does 
not count, but the species. Once the survival of this 
is ensured the individual may disappear. 

A similar phenomenon of auto-intoxication is mani- 
fested by lower vegetables, yeasts, and microbes. 
Pasteur, who discovered the microbe of lactic fermen- 
tation, found that this micro-organism, which itself 
produces lactic acid, perishes because of the over- 
production of this substance. Yeasts, again, cannot 
bear an excess of alcohol, their own product. Thus 
the vegetable kingdom offers us examples of the 
absence of natural death as well as examples of a 
natural death due to an auto-intoxication of the 

In the animal kingdom examples of natural death 
are also to be found, but only very exceptionally. 
Those examples are provided by Rotifera (inferior 
worms) and by Ephemeridae. Their adult life is 
reduced to the sexual act, almost immediately followed 
by death without an external cause. Their life is so 
short that they do not even feed and lack developed 
buccal organs. That in itself constitutes an organic 
cause of inevitable, i.e. natural, death. 



Among human beings natural death is extremely 
rare. It sometimes occurs in very old people, under 
the shape of a peaceful last sleep. The likeness it 
bears to sleep is so striking that Metchnikoff thought 
himself authorised to form the following hypothesis 
concerning the analogy in their mechanism. 

According to a theory of Preyer's, fatigue and sleep 
are due to a periodical auto-intoxication set up by 
the products of the vital activity of our organism. 
These products are destroyed by oxidation during 
sleep, after which fatigue disappears and awakening 
comes. According to Metchnikofi it may be that the 
mechanism of natural death also consists in an auto- 
intoxication by the progressive accumulation of toxic 
products during the whole of life. The analogy be- 
tween sleep and natural death allows the supposition 
that, as before going to sleep an instinctive desire for 
rest is felt, in the same way natural death must be 
preceded by an instinctive desire to die. Moreover, 
this is confirmed by concrete examples. Thus that of 
an old woman of ninety-three who expressed that desire 
in the following terms to her great-nephew : " If ever 
you reach my age, you will see that death becomes 
desired just like sleep." The same thought had been 
expressed by the biblical patriarchs who fell asleep 
satiated with life. 

When, owing to the progress of Science, men reach 
the development of the instinct of death, they will 
look upon Death with the same calm as do very old 
people, and it will cease to be one of the principal 
causes of pessimism. It is for that reason that we 
must learn to prolong life and to allow all men to 
realise their complete and natural vital cycle, thus 
ensuring their moral balance. 


Psychological observations allowed Metchnikoff to 
conclude that pessimism is much more frequent in 
youth than in maturity or in old age. He attributes 
this to the gradual development of the vital instinct 
which is only completely manifested in middle age. 
Man then begins to appreciate life ; made wiser by 
experience, he demands less and is therefore better 

Metchnikoff proffers examples in support of his 
theory. He analyses the psychic evolution of Goethe 
as reflected in his Faust and describes that of "an 
intimate friend." These examples prove that natural 
psychological evolution already leads to a relative 
optimism. But, as long as senility is pathological and 
death premature, the apprehension that they inspire 
antagonises the normal evolution of optimism. A 
victory over those present evils will direct the normal 
course of life in the right way; one normal active 
period will succeed another ; the accomplishment of 
individual and social functions corresponding with 
each period will become realisable ; the death in- 
stinct will have time to develop, and Man, having 
been through his normal vital cycle, will sink, peace- 
fully and without fear, into eternal sleep. 


Researches on intestinal flora Sour milk. 

THE problem of our intestinal flora is so vast and so 
difficult that it demands years of research. Numerous 
facts had already been accumulated by Science on 
this subject, but it was still far from being elucidated. 

Certain scientists affirmed that microbes favour 
digestion by decomposing food residues in the intes- 
tine and are therefore not merely useful, but necessary 
to the organism. Others entertained a diametrically 
opposed opinion. The first thing, therefore, was to 
know which of the two opinions was founded on fact. 
Metchnikoff studied the case of the bat, in which the 
digestive tube is short and the large bowel not even 
differentiated. As he had supposed, a priori, in this 
animal, whose life duration is relatively long, the 
intestine contains few or no micro-organisms, which 
proves that digestion can be accomplished without 
their intermediary. Moreover, this was before long 
amply confirmed by the researches of MM. Cohendy, 
Wollman, and other scientists who succeeded in 
bringing up chickens and tadpoles in conditions of 
absolute sterility. 

Having acquired the conviction that microbes are 
not indispensable to digestion, Metchnikofi studied the 
part they play in the organism. It is universally 
admitted that the products of putrefaction are toxic, 



and lie enquired whether the intestine sheltered 
putrefying microbes. This question had not yet been 
solved ; certain bacteriologists thought that little or 
no putrefaction exists in a normal intestine. Metch- 
nikoff ascertained through systematic researches that 
the intestinal flora includes several kinds of putrefying 
microbes which secrete highly toxic products. 

With his pupils and collaborators, MM. Berthelot 
and Wollman, he carried out a series of experiments 
which established the fact that this intoxication is 
due to poisons of the aromatic group, such as phenols 
and indols. With these substances, they succeeded 
in artificially provoking arterio-sclerosis in the organs 
of animals, and also other modifications similar to 
those which are observed in senility. Having proved 
that putrefying microbes provoke the intoxication 
of the tissues, Metchnikoff set to work to find a 
means of struggling against those microbes. 

It was known that they could only live in an 
alkaline medium which is precisely that of the intes- 
tinal juices. Metchnikoff thought that if means were 
found to render the intestinal contents acid, without 
harm being done to the organism, the putrefying 
microbes might thus be destroyed. It had been 
known for a long time that sour milk does not 
suffer putrefaction, that being prevented by the acid 
fermentation. The lactic microbes of this fermenta- 
tion must therefore be antagonistic to the putrefy- 
ing microbes. He drew a conclusion in favour of 
the utility of sour milk, containing acid-producing 
microbes ; once introduced into the intestine, these 
should prevent the breeding of the noxious microbes 
which require an alkaline medium. 

His hypothesis seemed confirmed by the fact that 


populations who feed almost exclusively on curded 
milk live a very long time. In Bulgaria, for instance, 
whole villages, thus fed, are known for the longevity 
of their inhabitants. Starting from these considera- 
tions, he made experiments upon himself and system- 
atically introduced into his diet sour milk carefully 
prepared with pure cultures of certain lactic bacilli. 
His health was benefited by it, and his friends followed 
his example. Certain doctors recommended sour 
milk, the use of which gradually spread as a hygienic 
food. Metchnikoff considered the result acquired as 
a first step towards the artificial transformation of 
the wild intestinal flora into a cultivated and useful 

Unfortunately, the study of the intestinal flora is 
extremely complicated because of the innumerable 
species of micro-organisms and the extreme difficulty 
of disentangling the many influences which cross each 
other. He therefore considered collective researches 
as indispensable, the life and science of one man being 
insufficient to solve so vast a problem. Up to a 
certain point he succeeded in realising this scientific 
collaboration within his own laboratory. 


The Nobel Prize Journey to Sweden and to Russia A day with 
Leon Tolstoi. 

IN 1908 Metchnikoff received the Nobel Prize, together 
with Ehrlich, for his researches on immunity. Accord- 
ing to the statutes of that prize, the laureate is invited 
to give a lecture in Stockholm. Metchnikoff chose for 
his theme the " present state of the question of im- 
munity in infectious diseases," and, in the spring of 
1909, we went to Sweden and thence to Russia. The 
whole journey was a series of fetes and receptions in 
his honour. He was touched and grateful at this 
welcome, but with his usual humour, declared that 
it was the Nobel Prize which, like a magic wand, 
had revealed to the public the value of his researches. 

We only stopped for a short time at Stockholm, 
where the kindest hospitality was shown to Metch- 
nikoff. Sweden made an unforgettable impression 
upon us. Her deep, dark waters, wild rocks, and 
sombre pines make of it a land of legends. Elie was 
impressed not only by Nature in Scandinavia but 
also by Scandinavian Art, which reproduces it admir- 
ably. He was specially pleased with Lilienfiorse's 
pictures, representing animals against a background 
at the same time real and legendary. 

We went to Russia by way of the Baltic. The 
nights at that time were " white," and rocky islands 


covered with pines emerged from the sea like ghosts, 
in the mysterious silvery midnight light ; the im- 
pression was fairy-like. 

A warm welcome awaited Metchnikofi in Russia. 
At Petersburg, as in Moscow, he was received with 
cordial and enthusiastic sympathy not only by scien- 
tific and medical societies, but by all the intellectual 
youth of those cities. This warm reception contri- 
buted to efface the bitterness sometimes aroused in 
him by distant recollections of the reasons which 
caused him to leave his native country. 

During our stay in Russia we made the acquaint- 
ance of our great writer, Leon Tolstoi. We spent a 
day with him in his estate, lasnaia Paliana, and the 
day left a lifelong impression upon us. 

It was at dawn that we reached the little railway 
station where a carriage had come to meet us. It 
had been raining in the night and now, in the first 
morning light, everything shone with dew. We were 
excited by the sight of the Russian country, cool 
meadows, forest, fields, all that simple landscape that 
we had not seen for so long, and we were also greatly 
moved at the idea of meeting Tolstoi. 

The village appeared in the distance and, a little 
way apart, the wide open entrance gate of the old 
park of lasnaia Paliana. We entered a long shady 
avenue leading to the home of Tolstoi. The spring 
was at its best, flowers and perfumes everywhere. 
The house and the old park had the poetic charm of 
the ancient " nests of nobility " in Russia. 

Tolstoi's daughter greeted us on the steps ; her 
kindly simplicity at once put us at our ease. We 
had hardly entered the vestibule when we saw Leon 
Tolstoi himself coming down the stairs with a brisk 


step. We knew him at once, though he seemed to 
us different from all his portraits. We were first of 
all struck by his eyes, deep, piercing, and yet as clear 
as those of a child. He had nothing of that hard- 
ness and severity that one is accustomed to see in his 
portraits ; his features, too, seemed to us much finer 
and more idealised. He looked straight into our eyes 
as if he wished to read the depths of our souls. But 
we were at once reassured by the kind and benevolent 
expression of his whole face. He looked strong and 
healthy and did not seem old, but full of inner life. 
After the first words of welcome, he said to us, " You 
resemble each other ; that happens after living 
happily together for a long time." He questioned us 
concerning our journey and on the impression made 
upon us by Russia after our long absence ; then he 
said he had to finish his morning task. 

His daughter and son took us for a walk through 
the park and the village, and the friendly words they 
exchanged with the peasants indicated excellent 
relations between the villagers and the people of the 
chateau. As soon as we came in, Leon Tolstoi re- 
appeared, declaring that he gave himself holiday for 
the day. He questioned Metchnikoff on his researches, 
on the present state of hygiene, and on the application 
of scientific discoveries. He listened attentively and 
with visible interest. At the end of the conversation 
he declared that it was quite erroneously that he was 
thought to be hostile to Science, and that he only 
denounced pseudo-science, which has nothing to do 
with human welfare. " In reality," he said, " you and 
I are aiming towards the same goal by different lines." 

All his words were impregnated with a deep 
love for, and an ardent desire to serve, humanity. 


Literature and Art were mentioned ; Tolstoi said 
that lie was now so far from it all that he had 
even forgotten some of his own works and appreciated 
them much less than his writings on spiritual ques- 
tions. He thought that sometimes beauty of form 
acted at the expense of the moral bearing of the sub- 
ject. To the objection that Art embellishes Life, he 
answered that it has some value in that it serves as 
a link between men and makes them purer, but that 
its moral importance surpasses its aesthetic value by a 
great deal. 

He related that he had conceived a new work on 
the social movement in Russia and, a propos of that, 
the conversation fell upon political reprisals. The 
subject of deportations, prisons, and executions was 
visibly painful to him ; his eyes, now sad and suffering, 
revealed his vibrating soul. 

On the agrarian question, he was in favour of the 
nationalisation of land, and showed great enthusiasm 
for Henry George. He thought the suppression of 
the commune in Russia a great mistake. Metchnikoff 
explained to him that his personal observations in 
Little Russia spoke, on the contrary, in favour of 
individual property, which gave better agricultural 
results. Tolsto'i manifested perfect tolerance, and 
conversation flowed on peacefully concerning various 
subjects. In everything he said the beauty and eleva- 
tion of his soul was perceptible. 

After lunch he desired to have a serious conversa- 
tion with Metchnikoff and took him out driving, he 
himself holding the reins. On the way he returned to 
the question of Science. He thought that humanity 
was so overwhelmed with misery and had so many 
urgent questions to solve that work ought to be 


turned in that direction, and that we had no right to 
busy ourselves with abstract questions unrelated to 
life. " What good can it do man to have a notion 
of the weight and dimensions of the planet Mars ? " 
he said. 

MetchnikofT answered that theory is much nearer 
to life than it seems, and that many benefits have been 
acquired for humanity by scientific observations of 
an abstract order. Thus, the discovery of the great 
unchanging laws of Nature give to Man the conscious- 
ness of being submitted to logical laws instead of 
an arbitrary force, and that is a benefit. When 
microbes were discovered, their part in human life 
was not suspected, and yet this discovery was after- 
wards of the greatest service to human welfare since 
it enabled man to fight against disease. 

On the way back, Tolstoi gave his place to his son 
and himself returned on horseback, an exercise in 
which he indulged almost daily, in spite of the 
approach of his eighty years. He still rode 
splendidly, sitting quite upright, and seemed even 
younger than before. 

After that he went to take a little rest, whilst 
Countess Tolstoi gave us immense pleasure by reading 
to us two yet unpublished works by her husband, 
the charming story After the Ball and the tragic 
Sergius the Monk. 

In the late afternoon a friend of our host, an 
accomplished musician, sat at the piano and played 
some Chopin. In the spring twilight the charm of 
that music rilled us with emotion. Leon Tolstoi", 
seated in an armchair, listened ; the lyrical beauty of 
the sound sank deeper and deeper into his soul, his 
eyes became veiled with tears, he leant his forehead 


on his hand and remained motionless. Metchnikoff 
also was deeply moved, and the effect of music on 
two such men, the pleasure that it gave them, was 
the strongest plea in favour of pure Art. 

" I do not know what takes place in my mind 
when I listen to Chopin," said Tolstoi a few moments 
later, after the closing sounds had vanished, " Chopin 
and Mozart move me to the depths. What lyrism ! 
what purity ! " Metchnikoff liked Mozart and Beet- 
hoven, but Tolstoi thought Beethoven too compli- 
cated. As to Wagner and modern music, they both 
agreed about it, thinking it unintelligible and lacking 
harmony and simplicity. 

Around the tea-table conversation turned on 
senility, and Metchnikoff developed his theory of the 
discords of human nature. He illustrated his affirma- 
tions by the example of Goethe's Faust, who, accord- 
ing to him, formed the best picture of the evolution 
of human phases. To his mind the second part of 
Faust is but an allegory of the disharmonies of old age. 
It is a striking picture of the dramatic contest between 
the yet ardent and juvenile feelings of old Goethe 
and his physical senility. Tolstoi seemed interested 
by this interpretation and said he would read the 
second part of Faust over again, but that he himself 
would never offer an example of a similar lack of 
harmony. A propos of Metchnikoff's theory, accord- 
ing to which the fear of death exists because Death 
itself is premature, Tolstoi affirmed that he had no 
fear of death, but added, laughingly, that he would 
nevertheless try to reach the age of 100 in order to 
please Elie. 

Our train only left late in the night, and, until we 
started, the conversation never ceased to be animated. 


In every one of his words Tolstoi's exalted soul was 
perceptible, a soul in which there was room but for 
preoccupations of a spiritual order. He would have 
given the impression of floating above the earth if 
his ardent and compassionate heart had not constantly 
brought him back to the miseries and faults of 
human beings. The atmosphere around him was 
pure and vivifying as on high peaks, and the place 
seemed sanctified by his presence. 

That interview had been a meeting of two superior 
minds, two exalted souls, but how different ! The 
one, scientific and rational, always leaning on solid 
facts in order to soar and to spread his wings in the 
highest spheres of thought ; the other an artist and 
a mystic, rising through intuition to the same spiritual 
heights ; both pursuing the same goal of human per- 
fection and happiness, but going along such different 
roads. . . . 

As we took leave of him, Leon Tolstoi said, " Not 
farewell, but au revoir ! " And as we sat in the 
carriage and started to go, he appeared in a lighted 
window, as in an aureola, waving his hand, " Au 
revoir, au revoir ! " he repeated for the last time. 
. . . The night was calm and beautiful under the im- 
mensity of the starry vault, and its greatness was 
confounded in our souls with the greatness of Leon 


Intestinal flora Infantile cholera Typhoid fever Articles on popular 

WHEN he returned home, Metchnikoff immediately 
resumed his work. He continued, with his colla- 
borators, researches on the normal intestinal flora 
and on the microbian poisons which provoke arterio- 

They were able to ascertain that certain microbes 
of the intestinal flora, such as the bacillus coli and 
Welch's bacillus, produce poisons (phenol and indol) 
which are reabsorbed by the normal intestinal walls 
and which provoke arterio-sclerosis and other lesions 
of the organs. A part of those poisons is eliminated 
by the urine, and the quantity found therein allows 
one to estimate the quantity contained in the 
organism. An exclusively vegetarian or carnivorous 
diet increases its production, while a mixed diet 
reduces it. During the rest of his life MetchnikofE 
made systematic and periodical analysis of his own 
urine in correlation with his diet. 

From certain facts and certain experiments he con- 
cluded that the reciprocal influence of microbes might 
be utilised to attenuate or to eliminate the noxious 
action of some of them. Thus, by cultivating the 
lactic bacillus in the presence of those microbes which 
produce poisons belonging to the aromatic group, the 



decrease in quantity and even the disappearance of 
phenol and indol is observed. All those facts con- 
firmed anterior results which Metchnikoff had ob- 
tained, and indicated the route to be followed in his 
struggle against those toxins which gradually poison 
the organism and induce premature senility. 

Having thus elucidated certain questions concern- 
ing the part played by microbes in a normal organism, 
he studied the pathogenic intestinal flora. He began 
by infantile cholera because this question is simplified 
by the fact that new-born children are fed exclusively 
on milk. It was then believed by practitioners that 
this intestinal disease of infants came from their 
mode of feeding, from summer heat, and other external 
influences. Metchnikoff, however, succeeded in demon- 
strating that the 'contents of the intestines of infants 
suffering from " cholera " always included a special 
kind of microbe, the B. proteus ; he was also able to 
give the disease to young anthropoid apes by making 
them ingest food soiled by the intestinal contents 
of sick infants, thus establishing the infectious char- 
acter of infantile cholera. 

He then attacked another intestinal disease, 
typhoid fever, of which the microbe (Eberth's bacillus) 
had been known for some time, but had not been 
studied experimentally, ordinary laboratory animals 
being refractory. Metchnikoff had again recourse to 
anthropoids, and succeeded in infecting a chimpanzee 
by making him eat food soiled by the intestinal con- 
tents of a typhoid patient. 

With the collaboration of Dr. Besredka, he under- 
took a series of experiments on anthropoid apes and 
on macaques. The former alone took typical typhoid 
fever, similar to that of man. It could be given them 


by pure cultures of Eberth's bacillus, which definitely 
confirmed the specificity of that microbe. 

Antityphoid vaccination by means of killed bacilli 
not being at that time either safe or durable, Metch- 
nikofE advised measures of simple preventive hygiene : 
the use of cooked food, great personal cleanliness, 
cleanliness of streets and dwellings, and the destruction 
of insects, especially flies, which often infect food. 
In order to popularise these notions, he wrote a series 
of articles in newspapers. Later, several scientists 
found efficacious means of vaccination against typhoid 

In 1912 Metchnikoff, in collaboration with Dr. 
Besredka (the author of the antityphoid vaccination 
method by means of sensitised bacilli), demon- 
strated on anthropoid apes that antityphoid vaccina- 
tion by living sensitised microbes is certain, and 
that it presents no danger of diffusing the disease, for 
these microbes, harmless to the vaccinated individual, 
cannot prove a source of danger for his entourage, 
since they are phagocyted at the very place where 
they are inoculated. 

MetchnikofE always considered that it was very 
useful to keep the public at large informed of the 
results acquired by Science, because "it is only by 
becoming a part of daily life that measures of hygiene 
and prophylaxis will have efficacious results." He 
therefore lost no opportunity of spreading scientific 
principles and facts. In 1908 he had given in Berlin 
a lecture on " The Curative Forces of the Organism." 
In a Russian review, the Messenger of Europe, he 
developed the same subject and included an epitome 
of his lecture in Stockholm on immunity. In that 
article he expounded the phagocyte theory of im- 


munity. Among concrete examples of its application, 
he quoted the indications concerning the evolution of 
an infectious disease provided by the quantity of 
leucocytes in the blood, and the process employed 
by certain surgeons to diminish the danger of infec- 
tion during an operation : just as, in case of an enemy 
menace, the Government mobilise an army, certain 
surgeons employ divers means to attract an army of 
phagocytes and to stimulate their activity in case 
any microbes should penetrate into the wound. 

In 1909 he gave another lecture at Stuttgart, " A 
Conception of Nature and of Medical Science," in 
which he summed up his two works fctudes sur la 
nature humaine and Essais optimistes. The title 
of this lecture was intended to emphasise his view of 
human nature, according to which " Man, as he 
appeared on the earth, is an animal and pathological 
being belonging to the realm of medicine." But he 
ended his paper by the same optimistic thought which 
illumines the whole philosophy of his later years. 
" With the help of Science, Man can correct the im- 
perfections of his nature." 

He unveiled these imperfections and the ills which 
proceed from them, not only from a love of truth or 
scientific honesty, but always with the object of 
rinding means to combat them. He never allowed 
sight to be lost of the fact that Science lights up 
the tortuous and painful path which leads to an issue 
that suffering humanity will find by gradually widen- 
ing the limits of knowledge with the help of Work and 

of wm. 

Thus all his writings offer us encouragement and 


A bacteriological expedition to the Kalmuk steppes, 1911. 

DURING his preceding journeys in the Kalmuk steppes, 
Metchnikoff had often heard it said that tuberculosis 
was almost unknown there, but that the Kalmuks 
took it very easily when brought into contact with 
foreigners. As all means of combating this disease 
had hitherto given very unsatisfactory results, Metch- 
nikoff thought that researches should be started along 
a new path. He had long thought that observations 
on the extreme liability of Kalmuks to tuberculosis 
might perhaps provide some new data. But the 
study of the question necessitated a very distant 
journey which he now at last had the opportunity of 

According to Metchnikoff s hypothesis, a natural 
vaccination takes place among us against tuberculosis 
which would explain the resistance of the majority 
of human beings in spite of the enormous diffusion 
of the disease. He concluded that some attenuated 
breeds of microbes become introduced into our 
organism during our childhood, thus vaccinating us 
against the virulent tuberculous bacillus. This sup- 
position seemed to him plausible, for he had long 
ago found that some micro-organisms (Cienkovsky's 
bacillus, the cholera bacillus, etc.) become modified 
in different environment and conditions, both in form 


and in virulence. He had described this phenomenon 
in 1888 in a memoir entitled Pkomorphism of 
Microbes. His hypothesis would explain the liability 
of the Kalmuks, since, if no tuberculous bacilli 
existed in the steppes, the inhabitants could not 
acquire a natural vaccination. When placed in an 
environment which was not free from tuberculosis, 
they became infected very easily, being in no wise 
prepared for the struggle against the virus. 

The expedition to the Kalmuk country was there- 
fore planned in order to ascertain whether tuber- 
culosis was really absent from the steppes. This could 
easily be done by Pirquet's test, 1 which at the same 
time would show whether the number of Kalmuks 
infected increased from the centre to the outer limit 
of the steppes and corresponded with the greater 
degree of contact with the surrounding population. 
If the enquiry confirmed the hypothesis, there would 
remain to be seen which microbes might best be used 
as vaccines. 

The expedition was also intended to elucidate a 
few questions on the etiology of endemic plague in 
the Kirghiz steppes. When this intention became 
known, the Russian authorities desired to add to it 
a local mission on the study of plague epidemics in 
the steppes. Metchnikofi, who was chiefly concerned 
with the question of tuberculosis, was only able to 
draw up a plan of work for the Russian mission and 
to start it going in one of the plague centres. 

The Pasteur Institute expeditionary party com- 
prised, besides Metchnikofl, MM. Burnet, Salimbeni, 
and lamanouchi. They were joined at Moscow by 

1 A cutaneous scarification by tuberculin which provokes local inflam- 
matory redness on the scarified point in tuberculous subjects only. 


Drs. Tarassevitch and Choukevitch, and at Astrakhan 
by the physicians of the Russian plague mission. 
The Institut Pasteur party left Paris on May 14, 1911, 
full of spirits ; Metchnikoff, eager to make the journey 
pleasant for his companions, was doing the honours 
of his country to the best of his ability ; he fully 
succeeded, owing to the warm welcome and liberal 
hospitality which they received in Russia, where 
every one tried to contribute not only to the success 
of the expedition but to the comfort and pleasure 
of its members. The latter, indeed, preserved a most 
pleasant recollection of this journey, and, in later 
years, always spoke of it with pleasure. 

Navigation on the Volga from Nijni Novgorod to 
Astrakhan was full of peculiar charm. That five days' 
journey was one of the rare periods of complete 
rest in Metchnikoff 's life. He indulged in the dolce 
far niente as he watched the peaceful landscape on 
the passing banks. The Volga, then in flood, covered 
immense spaces. Here and there, whole forests 
emerged from the river which reflected them as in an 
enchanted dream. From time to time, little isolated 
villages appeared with the gilt cupola of a church 
or a monastery, then meadows, forests, steep cliffs, 
or gentle slopes down to the river. What poetry, 
what grandeur in simplicity ! As in a kaleidoscope, 
types of varied populations and pictures of local 
customs followed upon each other. 

Along the banks now and then were seen proces- 
sions of pilgrims. Their humble, gray, stooping 
figures breathed deep faith and resignation. Some- 
times popular songs arose from the Volga, sad, 
expressive, soul-penetrating chants. 

This contemplative quietude was only interrupted 


by stations in the ports of large towns where deputa- 
tions of the educated inhabitants came to wish the 
mission welcome. These functions had a cordial 
and touching character, for it was obvious that such 
enthusiastic demonstrations had for their source a 
sincere cult for the knowledge whose representatives 
were being feted ; it was touching to see such a living 
ideal in this distant and oppressed land. 

At Tsaritsine, several Kirghiz embarked on our 
boat in order to go to a large fair which the inhabitants 
of the steppes attended in numbers. Metchnikoff 
thought this was a unique opportunity to learn whether 
there were any carriers of the plague bacillus among 
those many natives coming from all parts of the steppes. 
He therefore decided that those members of the ex- 
pedition who had come to study plague would go to 
the fair with the Kirghiz, whilst he, with the rest of 
the expedition, would make observations on the 
Kalmuks of the Astrakhan region. 

A most hospitable welcome awaited us there ; people 
vied with each other in their efforts to assist the 
expedition. The Governor-General of Astrakhan had 
ordered all preparations to be made, and the mission 
was provided not only with necessaries but with com- 
forts which did much to alleviate the fatigue of the 
long journey. 

Whilst waiting for our companions, we had time 
to verify several diagnostical reactions, the Kalmuks 
lending themselves willingly to the operation. We 
heard later that they thought they were being vac- 
cinated against small-pox, a disease much feared in 
the steppes. 

As soon as the plague mission arrived, we started 
towards the Kirghiz steppes, for there was a plague 


centre north of the Caspian Sea. When we were out 
at sea, an intense north wind began to blow the waves 
away from the Kirghiz bank, and soon the depth 
lessened to such an extent that we could make no 
progress. The sailors were perpetually making sound- 
ings, and their repeated cries of " Two and a half feet ! " 
became a regular nightmare. The situation seemed 
critical, and returning to Astrakhan was suggested ; 
an idea which infuriated Metchnikoff ; he would not 
hear of it. At last, after several incidents we reached 
the Kirghiz bank, the crossing having lasted three 
days instead of the usual twenty-three hours. 

As we arrived, we could see from afar a sort of 
Valkyries' ride of natives clad in brilliant colours and 
riding up at full gallop with wild cries and exclama- 
tions. Before us spread a barren and sandy steppe, 
producing the sad impression of a land forsaken by 
God and man. How could life be possible there ? 
But gradually, as we became captivated by the charm 
of the boundless space, the purity of the air, the 
harmonious colouring and the scent of wild heliotrope 
and wormwood which alone can grow in those sands, 
we began to understand that it was not only possible 
to live in those steppes, but also to love them. 

The plague centre stood among sandy hills with 
low-growing grass ; the summit of one of them was 
black with charred remains of burnt objects ; the 
corpses were buried in the same place. Only a few 
wretched forsaken hovels remained. In order to 
throw light upon endemic plague in the steppes, it 
was first of all necessary to ascertain whether the 
plague microbes remained alive for some time in 
places where the scourge had raged ; if they were 
preserved in dead bodies which had been singed 


rather than burnt ; if the worms, insects, rodents, and 
domestic animals on the spot were or were not carriers 
of the plague microbe, and could or could not transmit 
it to a distance from the initial focus. 

After organising a small emergency laboratory, 
the corpses were exhumed, and Dr. Salimbeni made 
a post-mortem examination. These corpses, having 
been in the ground for three months, were in a state 
of advanced decomposition and contained no living 

Having set the work of the plague mission going, 
Metchnikoff parted from it in order to accomplish 
the projected investigations on tuberculosis in the 
Kalmuk steppes. He made a very solemn entry 
into these steppes ; a Kalmuk deputation welcomed 
the mission and presented Metchnikofi with a bronze 

The aspect of those natives is sad and humble, 
their movements are slow, their eyes dull. In this 
they contrast with their neighbours, the quick and 
intelligent Kirghiz, and one reason for it is that the 
latter, being Moslems, absorb no alcohol, while the 
Kalmuks consume fermented milk (alcoholic fer- 
mentation) which poisons them slightly but con- 
tinuously ; this observation had already been made 
by Metchnikoff at the time of his previous visit. 

The Kalmuks live in tents covered with coarse 
felt ; they transport these dwellings on camels from 
one place to another when their herds of sheep or 
horses have consumed the scanty pasture grass 
around the camp. There is no attempt at cultivation, 
and the steppes become more and more barren as 
the pastures become exhausted. In order to remedy 
this evil, the Russian administration has begun 


various experimental plantations. In some places 
the steppes are covered with small tamarisk bushes 
or with silky grass, but, as a rule, the chief growth is 
of silver wormwood. The monotony is not so great as 
one might think, for the steppes, like a mirror, reflect 
all the divers light-changes, and wonderful natural 
phenomena take place there. During the great heat, 
mirages are to be seen in the distance a river, lakes, 
reed-grown shores ; sometimes a sand-storm super- 
venes, more infernal than fairy-like, called here 
" smertch." The wind raises the sand in tongues of 
flames or in funnels running up to the sky with giddy 
rapidity. Gradually, all the separate turmoils join 
in a gigantic wall of sand, advancing in an orgy of 
movement ; the heavy clouds fall towards the 
ground, the sand rushes upwards, everything becomes 
confounded in darkness and chaos. 

One feels so entirely in the power of natural forces 
that the fatalism of the poor inhabitants of the land 
is easily understood. The Kalmuks, primitive and 
nomadic, produce the impression of ghosts from 
distant "centuries. 

Metchnikoff noticed that since his last visit in 
1874, fatal influences had worked havoc on the 
population. Four scourges, all of them coming from 
outside, are destroying the Kalmuks : syphilis, 
alcoholism, tuberculosis, and the Russians who are 
constantly pushing them back. Those poor people 
realise the fate which is awaiting them, and resign 
themselves like a sick man who knows his sickness 
to be incurable. 

The spiritual life of the Kalmuks reduces itself to 
their religious cult. There are many Buddhist con- 
vents where children are being brought up for a 


monastic life. Religious rites are performed by 
priests dressed in purple and brilliant yellow ; for 
the uninitiated, their part consists in unrolling inter- 
minable bands on which prayers are inscribed, and 
in executing a religious music which seemed a mixture 
of a camel's grunt, a dog's howling, and an infinitely 
sad plaint. Of the pure cult of Buddha, nothing 
seems to remain but an empty form. However, 
there is a convent in the steppes Tshori a sort of 
religious academy, where an effort is being made 
to restore the cult to the original level of Buddhist 

Whilst gathering observations on tuberculosis, we 
traversed the steppes in a north-easterly direction as 
far as Sarepta. This town seemed like a civilised 
centre after the steppes, where the conditions of life 
were somewhat hard in spite of the cordial reception 
accorded us everywhere. The food, consisting solely 
in tinned goods and mutton, had caused intestinal 
trouble in nearly all the members of the expedition ; 
on the other hand, we were greatly incommoded by 
the heat, lack of water, and abundance of insects of 
all kinds. 

In spite of all, Metchnikoff had hitherto borne the 
journey fairly well. However, since we left Moscow 
he had had frequent cardiac intermittence, accom- 
panied sometimes by sharp pains along the sternum. 
But the stay at Sarepta especially tried his health ; 
the heat reached 35 C. (95 F.) in the shade and 52 C. 
(about 125 F.) in the sun ; in the evening the windows 
could not be opened because of the mosquitoes. 
Metchnikoff, who had shown so much endurance, 
now became weak, drowsy, and nervous ; he attri- 
buted his condition to the excessive heat. Yet he 


could not leave Sarepta, for all the members of both 
branches of the mission had agreed to meet there in 
order to sum up the results of their observations. 

The researches of the expedition for the study of 
plague were not finished, and the Russian mission 
had agreed to complete them. So far, it was estab- 
lished that neither the corpses after a certain time 
nor the ground, nor the surrounding animals con- 
tained any plague microbes, and no carriers had been 
found among the Kirghiz population. 

The data gathered among the Kalmuk population 
justified MetchnikofFs hypothesis. In the centre of 
the steppes, where the Kalmuks were still isolated, 
tuberculosis was completely unknown ; diagnosis 
reactions were negative. They became positive more 
and more frequently as we came nearer the periphery 
of the steppes and the Russian population. The 
extreme sensitiveness of the Kalmuks must there- 
fore depend on the fact that they have suffered no 
natural vaccination in the steppes, which would 
support the idea that some natural vaccine exists 
amongst us. Metchnikoff therefore concluded that 
he might direct ulterior researches towards the quest 
of natural tuberculous vaccines. Such were the 
scientific results of the expedition. 

Apart from that, the journey to Russia had a 
strong personal influence on Metchnikoff. He had 
formerly left his country under the impression of the 
fatal error committed by the revolutionaries in 
killing Alexander II., an error which had led to a 
protracted reaction. He had therefore remained very 
sceptical concerning the Russian revolutionary move- 
ment ; he thought that the necessary reforms might 
come from a Government evolution. But, during his 


sojourn in Russia, he was able to appreciate events 
which modified his ideas to a great extent. He was 
impressed by the contrast between the progressive 
aspirations of the " intellectuals " and the inertia or 
noxious activity of the rulers. The policy of Casso, 
the Minister of Public Instruction, who ordered 
regular raids in the universities, the persecution of 
Poles and Jews, the encouragement of the " black 
band " obscurantism, giving plenary powers to 
creatures of darkness like Rasputin and his peers, 
all these things excited indignation in a man who 
placed the free development of human culture above 

He thus ceased to count upon the progressive 
evolution of a Government which was incapable of 
solving the complicated problems of Russian life, and 
henceforward thought that those problems would be 
solved by the " intellectuals " apart from the Govern- 
ment and in opposition to it. 


Further researches on the intestinal flora Forty Years' Search for 
a Rational Conception of Life. 

SINCE Metchnikoff had conceived the idea that a con- 
siderable part was played in human life by the in- 
testinal flora, his thoughts had centred around a study 
which he thought profitable : that of the influence of 
intestinal microbes on the normal and on the patho- 
logical organism. 

So, on his return from Russia, he took advantage 
of the fact that an epidemic of infantile cholera had 
broken out in order to continue his former investiga- 
tions of that disease. The numerous cases which he 
thus studied allowed him finally to establish the 
specific part of the B. proteus as well as the similarity 
between infantile cholera and Asiatic cholera. This 
time he succeeded in contaminating, not only young 
anthropoid apes, but also new-born rabbits, and that 
not only through sick children's excreta, but by pure 
cultures of the proteus, which eliminated every doubt 
of the specificity of this microbe. 

Metchnikoff explained the contamination of chil- 
dren exclusively breast-fed, either by the presence of 
a carrier personally refractory, among the entourage, 
or by the transport of dirt, by means of flies, on the 
objects which infants so readily put into their mouths. 
He therefore advised preventive means of absolute 


hygiene and cleanliness, especially where suckling 
infants are concerned. 

During the year 1912, he studied the intestinal flora 
and the influence of divers food diets. He experi- 
mented upon the rat, an omnivorous animal whose 
mode of feeding resembles that of man. The rats 
were divided into three lots, of which one was kept 
to a meat diet, another to a vegetarian regime, 
and the third to a mixture of both. The meat diet 
was least favourable, and the best results obtained by 
the mixed food. 

These observations led Metchnikoff to the study 
of other problems intimately connected with the 
same question. 

He undertook a series of researches in collabora- 
tion with his pupils, MM. Berthelot and Wollman, on 
the conditions which cause the diminution within the 
organism of the toxic products of intestinal microbes. 
They found that the quantity of these products was 
very small in those animals which feed on vegetable 
or fruit containing much sugar, such as carrots, 
beetroot, dates, etc. This is explained by the fact 
that the products of the decomposition of sugar are 
acids which prevent the development of putrefying 
microbes. But the sugar, rapidly absorbed by the 
walls of the small intestine, only reaches the large 
intestine in a much reduced quantity, for it is only 
up to a certain point during its journey that the 
cellulose of vegetables, rich in sugar, protects that 
substance. The question, therefore, was to find the 
means of making it reach the large intestine in 
greater quantities. In the intestine of a normal 
dog, an innocuous microbe was found, the Glycobacter 
peptonicus, which decomposes starch into sugar. 


Metchnikoff made some laboratory animals ingest 
this microbe together with food, and ascertained that 
it reached the large intestine and decomposed in it 
the starch of farinaceous food into sugar, of which the 
acid products prevented the swarming of putrefying 
microbes. By this process it is possible to reduce to 
a minimum and even sometimes to eliminate the 
production of phenol and indol in rats subjected to 
a mixed diet and made at the same time to ingest 
cultures of the lactic bacillus and of the glycobacter. 

Metchnikoff applied these different diets to him- 
self and to other individuals and obtained concordant 

However, he ascertained that it is not only the 
food diet which regulates the quantity of microbian 
poisons contained in the organism ; that quantity 
sometimes varies very much in spite of an identical 
diet. He thought that a very important part of 
influence is due to pre-existing microbes which pre- 
vent or favour the development of microbes of putre- 
faction. All these questions, complicated by the 
richness and variety of the intestinal flora, still de- 
manded a long series of laborious researches. 

At the end of the winter he felt tired, and we 
went to the seaside during the holidays. But the 
sharp sea air did not suit him ; he had a beginning of 
cardiac asthma and nearly fainted during a walk. 
We therefore had to come away from the sea, and 
went inland, to Eu. At the beginning of our stay, 
Metchnikoff did not feel well, walking tired him, he 
suffered from cardiac intermittence ; it was only 
gradually that his condition improved and he was 
able to write the preface to a Russian edition of his 
philosophical articles. 


This book was entitled Forty Years' Search for a 
Rational Conception of Life, and the articles record 
the evolution of his ideas and his search " not only 
for a rational understanding of life, but also for the 
solution of the problem of death, which is so full of 
contradictions . ' ' 

This collection of articles enables us at the same 
time to follow the gradual transition from the pessim- 
ism of his youth to the optimism of his maturity. 
His first writings 1 relate to the discords of human 
nature and the lack of a solid basis for morals. 

But, already in 1883, he concluded an opening 
Causerie at the Naturalists' Congress in Odessa, by 
the following words : " The theoretical study of 
natural history problems, in the widest sense of the 
word, alone can give a sound method for the com- 
prehension of truth and lead to a definite conception 
of life or at least to an approach to it." 

Another article, The Curative Forces of the Organ- 
ism, sums up his phagocyte theory, and states the 
fact that the organism possesses special powers of 
struggle against enemy elements. 

In 1891, he wrote The Law of Life, in which we find 
the dawning idea that the lack of harmony in human 
structure does not make a happy existence and a 
rational code of morals impossible. Morals must 
consist " not in rules of conduct adapted to our 
present defective human nature, but on conduct 
based upon human nature modified, according to 
the ideal of human happiness." 

The Flora of the Human Body, published in 1901, 

1 Education from an Anthropological Point of View, The Matrimonial 
Age, The Conception of Human Nature, The Struggle for Existence in a 
General Sense. See Bibliography. 


is a study in which Metchnikoff 's optimism assumes a 
definite form, for he speaks of the efficacy of certain 
means of struggling with our lack of harmony. 

The last chapter in the book, " A Conception of 
Life and of Medical Science," introducing the word 
Orthobiosis, strikes the optimistic chord, winged and 
conclusive, which must result from victory over the 
disharmonies of human nature. This is Metchnikoff's 
ultimate formula, summing up the problems of life 
and of morals : 

The ethical problem reduces itself to this : to allow the 
majority of human beings to reach life's goal, that is, to accom- 
plish the whole cycle of a rational existence to its natural end. 
We are still very far from that. We can but sketch the rules 
to follow in order to attain this ideal. Its final realisation will 
demand more scientific researches, which must be allowed 
the widest and freest scope. It is to be foreseen that existence 
will have to be mollified in many ways. Orthobiosis demands 
an active, healthy, and sober life, devoid of luxury and excess. 

We must therefore modify present customs and eliminate 
those extremes of wealth and poverty which now bring us so 
many evils. As time goes on, when Science has caused present 
evils to disappear, when men no longer tremble for the life 
and welfare of their dear ones, when individual life follows 
a normal course then Man can attain a higher level and 
more easily devote himself to exalted goals. 

Then Art and pure Science will occupy the place which 
is due to them and which they lack at the present moment in 
consequence of our many cares. Let us hope that men will 
understand their true interests and contribute to the progress 
of orthobiosis. 

Many efforts are necessary, much self-sacrifice, but they 
will be attenuated by the consciousness of an activity 
directed towards the real goal of human existence. 


First our pleasures die, and then 

Our hopes, and then our fears, and when 

These are dead the debt is due. 

Dust claims dust and we die too. 


Unpleasant incidents The fabrication of lacto-bacilli St. Leger- 
en-Yvelines Return to Paris First cardiac attack Evolution 
of the death-instinct Notes on his symptoms. 

THE end of 1912 had some unexpected emotions in 
store for us. 

Metchnikofi had always been able to congratulate 
himself on the cordial hospitality which he had found 
in France, and to the end of his life he remained 
deeply grateful for it. 

But, in any country, incidents may occur about 
which it would be unjust to generalise when they are 
due to individuals or to particular limited circles, 
as was the fact in the present case. In spite of 
the broad and generous ideas so widespread in 
France, a sudden current of narrow nationalism 
became manifest, at this moment, in certain quarters. 
Foreigners were accused of invading the country, of 
occupying lucrative posts and increasing the diffi- 
culties of the bitter struggle for existence. At first, 
only vague allusions were made, but, little by little, 
the attacks of that nationalist circle went beyond all 
bounds of justice and decency and turned into brutal 

225 Q 


provocations. The contemptuous word meteque was 

One newspaper especially led a furious propaganda 
and hesitated at no means of overwhelming its 
victims, one of whom was MetchnikofE. 

Those coarse attacks might have been ignored 
with the contempt which they deserved had they not 
been echoed by a writer in a serious publication. 
Dr. Roux then wrote a reply in the same paper, and 
the campaign ceased. 

A proverb says with truth, " Slander away ! some- 
thing will always stick." And it was thus in this 
case. MetchnikofE was reproached with having made 
money by his scientific discoveries. The story of his 
whole life and the fact that he left no fortune should 
suffice to answer this calumny, yet I am obliged to 
dwell on it, though I should have preferred not to do 
so. The incident is too characteristic of MetchnikofE 
to be omitted in this biography, which must be a 
faithful testimony. The calumny was based on a real 
fact, but the interpretation of it was absolutely false. 
After MetchnikofE's experiments on the lactic bacillus, 
a notion of the hygienic power of pure sour milk 
began to spread among the public. A manufacturer 
had the idea of preparing it on a large scale, according 
to the new scientific principles, and wished to form 
a company to that effect ; he asked MetchnikofE to 
recommend to him some one whom he could entrust 
with the technical work of preparing the pure curded 
milk. It happened that we were just then trying to 
find a post for a young couple in whom we were 
interested, and whose child was my husband's god- 
daughter. He trained his protege in the technique 
required, and was therefore able to recommend him. 


A short time later, the manufacturer declared that he 
could not be sure of the success of his enterprise with- 
out the guarantee of the name of Metchnikoff, whose 
researches had proved the advantages of the prepara- 
tion in question. After consulting the legal adviser 
of the Pasteur Institute, Metchnikofi consented to 
this, without of course having any pecuniary interest 
in it ; the formula chosen was, " sole provider of 
Professor Metchnikofi." The undertaking succeeded, 
and our protege's future was assured. Metchnikoff 
himself, however, was attacked and accused most 
unjustly, though he had never made any personal 
profit whatever from the enterprise. And yet, when 
his friends told him that it had been very reckless on 
his part thus to expose himself, he answered that he 
thought it impossible to hesitate between the welfare 
of a whole family and the possibility of gossip. His 
reasoning was imprudent and perhaps erroneous, but 
he never hesitated between doing a kindness and the 
possible unpleasant consequences it might have for 
himself. If some people could not understand him, 
it was because he was far from the commonplace, 
" not like other people," a quality often misunderstood 
and unforgiven. 

Such are the facts. " Honi soit qui mal y 
pense ! " 

The desire to lessen the ills around him was, in 
general, the cause of heavy anxieties in his later years. 
He had learnt that the discovery of an industrial 
process, of which the realisation required capital, 
would be an excellent investment. He immediately 
wished to make his friends profit by it, as well as him- 
self, in order to alleviate material difficulties. But 
until the end of his life the undertaking had no 


results, and he was obsessed by the fear of having 
given bad advice to those who followed him. 

He knew not how to refuse, even when he should 
have done so ; therefore he was odiously exploited. 
Often he worked, in his rare leisure moments, for 
people who were unworthy of his kindness. During 
the last years of his life, all these incidents grieved 
him so much that he used to say he felt the burden 
of existence. His soul was darkened, he felt very 
depressed, and his health suffered. 

We spent the summer holidays of 1913 at St. 
Leger-en-Yvelines, a pretty place on the edge of the 
Rambouillet forest. In his choice of a holiday resort, 
my husband was always guided by the desire to find 
a place favourable to my sketching, and St. Leger 
answered the purpose wonderfully. The fields with 
their vast horizons, the forest with its graceful 
bracken and carpets of softly-tinted heather, the 
mysterious ponds, all went to compose an admirable 
symphony, full of artistic suggestion. 

Elie himself was gay and full of spirits. He 
worked in the morning, and we spent the rest of the 
day in the forest. He often read aloud ; he rested 
and enjoyed the peaceful calm, pure air, and verdure 
which he loved so much. 

He had arranged to take advantage of these 
holidays to execute work of which he had been think- 
ing for a long time. As it has been said above, he 
thought that the life instinct was only developed 
gradually and produced at the same time an optimistic 
conception of life ; he wished to verify this per- 
sonal impression by the psychological evolution of 
divers other thinkers. He turned to Maeterlinck, as 
a representative of modern ideas. This author, 


mystical and pessimistic in his youth, had acquired 
in his maturity a far more optimistic conception of 
life. He himself explained this change by the 
influence of circumstances, but MetchnikofE saw in 
it a deeper cause, connected with the progressive 
evolution of the vital instinct which, by bringing 
equilibrium with it, suggests optimism. The study 
of Maeterlinck's works confirmed his opinion. 

Time flowed peacefully between rest and these 
occupations ; at the end of the holidays, we con- 
gratulated ourselves on their result on my husband's 
health ; on our return, his friends thought him looking 
well. Yet on the 19th October, about seven in the 
morning, he had a terrible cardiac attack without 
any apparent cause. I found him seated at his desk, 
and was terrified by his appearance ; his lips were 
blue, and he was breathing with difficulty. And yet 
he was writing, and this is what he was writing : 

SfcvBES, 19th October 1913, 7.45 A.M. 

This morning, after a good night, my heart was working 
well ; I had from 58 to 59 regular pulsations. But, as I rose, 
I suddenly felt acute pain along the sternum ; at the same 
time began a strong crisis of tachycardia. I had never in my 
life felt anything like it. ... 

Here he had to stop as the crisis was becoming 
intolerable, but a few hours later he took up his pen 

19th October, 3 P.M. 

The crisis lasted till one o'clock (six hours' duration). 

There were times when the pain in the chest was unen- 

I was thirsty and drank hot, weak tea ; I vomited ; I felt 
wind hi the stomach and the intestine. About noon the 
pain decreased, but the heart-beats were frequent and extremely 


irregular. I lunched in order not to alarm my wife, though I 
feared to aggravate the attack by filling my stomach. 

But the opposite happened. From the first mouthfuls (I 
naturally eat very little) the pain became more tolerable 
and the pulse less frequent. After lunch, everything became 
normal again ; the pain ceased, the pulsations slackened (78- 
80 per min.) and became much more regular. Intermittence 
was rare, and I several times counted 100 regular beats in 
succession. I remained absolutely conscious during the whole 
crisis, and what chiefly pleased me is that I felt no fear of 
death, which I was expecting at every moment. It was not 
only reasoning which made me understand that it was better 
to die now, whilst my intellectual powers had not yet gone 
from me and I had evidently accomplished all of what I was 
capable ; I resigned myself also in feeling, and quite serenely 
to the catastrophe which was coming upon me and which 
would be far from unexpected. 

My mother, who had suffered from heart attacks during 
a great part of her life, died at 65. My father died of apoplexy 
in his 68th year. 

My eldest sister succumbed to an oedema of the brain ; 
my brother Nicholas died at 57 of angina pectoris. 

Undoubtedly my cardiac heredity is a bad one. Already 
in my youth, I suffered from my heart. At 33 I had such 
cardiac pains that sometimes I had to rest after walking a 
few paces. At 34, I had much giddiness and a feeling of 
heaviness in the head. I could not read a few lines, a poster 
even, without a painful sensation. In 1881, during relapsing 
fever, I had severe cardiac intermittence, very fatiguing and 
only relieved by small doses of digitalin. 

I afterwards had periodical attacks of intermittence but 
never any tachycardia, at least none that lasted more than a 
few seconds. A little tincture of strophanthus used to relieve 
me during intermittence. I ended by consulting Dr. Vaquez, 
but the treatment he prescribed gave me no relief. As I 
attributed my condition to poisoning by the toxins of intestinal 
microbes, I resolved to give up raw food and to purge myself 
now and then with Carabana water. The success of this 


treatment was indisputable, and in 1897 the intermittence 
ceased. In the autumn of 1898 I was beginning to suffer 
from polyuria ; I consulted Albaran, who counselled ContrexS- 
ville water, but this cure caused the appearance of albumen 
in my urine. In 1898 I consulted Norden at Frankfort and 
Leube in Paris during the Exhibition of 1900. Neither found 
anything alarming. Norden had told me that I had symp- 
toms of arterio-sclerosis inherent to my age (53). I adopted a 
mixed diet ; I took, regularly, sour milk prepared with 
cultures of the Bulgarian lactic bacillus, and, during some 
years, my health was quite satisfactory. 

It was only after my journey to Russia in 1909 that a 
notable aggravation supervened. I felt acute pains in the 
chest, along the sternum, especially after eating or walking. 

In 1911 the intermittence reappeared. In January 1911, 
I consulted Dr. Heitz in order to know whether I could under- 
take an expedition in the Kalmuk steppes, where hygienic 
conditions are very unfavourable. Dr. Heitz found my heart 
hypertrophied, some slight galloping noise, the blood-pressure 
(Pachon's apparatus) 17-16-15. He said, however, that I 
might undertake the journey, but added, " People die suddenly 
with less the matter than that with their hearts." The journey 
went well, though I suffered from frequent intermittence and 
pains along the sternum when I walked. 

After my return, my heart was fairly satisfactory. 

What consoles me especially is that I have preserved my 
activity, my passion for work, and my intellectual powers. 
But, naturally, I am ready to die at any moment. 

At the beginning of the summer I was sounded by Dr. 
Manoukhine and Professor Tchistovitch ; both thought the 
heart-sounds satisfactory, but Manoukhine was rather struck 
by the weakness of the first aortic sound whilst the second was 
very strong. I had frequent intermittence, but with intervals 
of normal pulsations. Latterly I have felt better in that 
respect, and the pain along the sternum only occurred in 
exceptional cases. 

Whilst preparing for my end, I am glad that I can face it 
with courage and serenity. 


As I look back upon my life, it seems to me to have been 
as " orthobiotic " as possible. 

If it may seem premature to die at 68 years and 5 months, 
it must not be forgotten that I began to live very early (I 
published my first scientific work at 18) ; that I have had 
many emotions during my life ; that I was, so to speak, in a 
state of continual ebullition. 

The polemics concerning phagocytosis might have killed or 
finally enfeebled me much earlier. At times (for instance, I 
refer to Lubarsch's attacks in 1889 and those of Pfeiffer 
in 1894) I was ready to rid myself of life. 

Moreover, I only began to follow a rational hygiene (accord- 
ing to my opinion) after I was 53 years old and already had 
symptoms of arterio-sclerosis. I have been fairly successful 
in combating intestinal putrefaction (phenols and indols), 1 
but I could not succeed in getting rid of abundant clostridium 
butyricum which were implanted in my intestine. 

To sum up, I rejoice that I have had an existence not devoid 
of sense, and I feel some satisfaction in considering my con- 
ception of the problem of life as being accurate. 

As I prepare to die, I have not the shadow of a hope of a 
life beyond, and I calmly look forward to complete annihilation. 

It is possible that having very early begun a very intense 
life, I have attained at 68 a precocious satiety of living, just 
as certain women cease to menstruate earlier than the great 
majority. EL. METCHNIKOFF. 

P.S. I believe everything is in order in view of my end 
(my will, my affairs, etc.). 

P.S. Let those who think that, according to my principles, 
I should have lived a hundred years, " forgive " me my pre- 
mature end in view of the extenuating circumstances above- 
mentioned (intense and precocious activity, excitable tempera- 
ment, nervous disposition, and late beginning of the rational 
diet). E. M. 

1 28th June 1914. I have again analysed my urine and I again find 
indican in fairly large quantities in spite of a diet which is as rational as 
possible. I am trying to elucidate this strange contradiction. 


The very next day he felt well enough to return 
to his work. 

When urged to settle down in Paris in order to 
avoid the fatigue of the journey, he replied that the 
peace and pure air of Sevres were indispensable to 
his health, that the journey did not fatigue him in 
the least, but on the contrary provided him with 
wholesome exercise and a pleasant walk. Knowing 
how prudent he was, I did not dare to insist for fear 
of mistaking what was really best for him. And life 
gradually resumed its normal course. . . . 

For a long time Metchnikofi had been observing 
himself very attentively ; he took regular notes on 
the influence of the food diet which he followed ; by 
the analysis of his urine, he sought for indications 
respecting the toxic products of his intestinal flora ; 
he studied upon himself the advance of senility, 
whitening of hair, etc. 

Since his crisis he had adopted the habit of writing 
occasional notes on his psychical state. This is what 
he wrote on the 23rd December 1913 at Sevres : 

Two months and more have passed since I wrote the pre- 
ceding lines. During that period my health has been satis- 
factory ; nevertheless I have wondered every day whether it 
would be my last. 

I am therefore hastening to write my memoir on infantile 

The cardiac intermittence has been more or less frequent, 
yet every day I have had periods of regular pulsations (58-66-72 
per minute) as usual. 

The day before yesterday I contracted a bad cold, 
accompanied by a little fever. Wondering if it would de- 
generate into pneumonia, I faced anew the possibility of a 
near end, and I resumed the analysis of my thoughts, feelings, 
and sensations. 


As my 70 years draw near to their close, it seems to me 
that a feeling of satiety with life, what I call the " natural 
death instinct," is gently beginning to evolve. 

When, in autumn 1910, experimenting with typhoid 
cultures, I had soiled my face and mouth, I naturally said 
to myself that it might give me typhoid fever. I washed my 
face and beard with soap and a solution of sublimate without 
considering that I was safe against the infection. I reasoned 
that it would be preferable to contract the disease and to die 
of it. (At my age typhoid fever is almost always fatal. I 
had never had it, and might therefore consider myself in a 
state of receptivity.) It is fine to fall on the battlefield, 
especially at an age when life and activity are already on 
the wane. But all that was pure reasoning ; instinctively I 
still felt a great desire to live, and it was with joy tha 4 } I 
counted the days which separated me from the danger of 
having contracted typhoid fever. I felt much relieved a 
fortnight after the incident, considering that the limit of 
incubation was passed. 

Thus reasoning and feeling or instinct were not in accord. 

Since then, in the three following years, a modification has 
taken place in my psychical condition. 

The prospect of death frightens me less than before. During 
my cardiac crisis of the 19th October 1913 I even felt no fear of 
death, and my satisfaction at my recovery was less than before. 

I think it is that difference in quantity which constitutes 
the first symptoms of indifference towards death, an indiffer- 
ence which is hardly perceptible at first. 

Satiety with life is sometimes observed in old people of 
80 ; it is not surprising to feel the first approach of it 
about 70, especially in the case of a man like myself who 
began very early to lead a very intense life. 

Other special circumstances influence even more this 
precocious satiety of life. As I become more indifferent to 
my own life I feel a more and more acute anxiety for the 
health, life, and happiness of those who are dear to me. 

I am especially troubled by a consciousness of the im- 
perfection of modern medicine. In spite of the progress 


realised in these latter days, it is still powerless against a 
multitude of diseases, threatening us on all sides. 

Pulmonary lesions (tuberculosis, pneumonia, etc.), the 
nephrites, and an infinite quantity of other diseases can 
yet neither be prevented nor cured. So we live in constant 
fear for those we love. When medicine shall (as I am per- 
suaded) have conquered all these evils, one cause of the 
bitterness of life will cease but that is not yet the case. 

That is why, besides the weakening of the life-instinct, a 
resignation towards death grows in us, as a means of no 
longer feeling the ills which afflict our neighbours. 

With time, when that source of unhappiness has been 
eliminated by medicine, old age will be more attractive, and 
an orthobiotic life will become normal and realisable. 

At the ages of 50, 60, 65, I felt an intense joy in 
living, such as I described in my Studies on Human Nature 
and Optimistic Essays. In the last few years it has lessened 

Scientific work still provokes in me an invincible enthusi- 
asm, but I am becoming more indifferent to many of the 
pleasures of life. 

And indeed he no longer had the joyous soul of 
former days ; into his life a funereal note had crept, 
low but continuous and obstinate. He gave all the 
more energy to the study of those questions the 
solution of which was to bring about the reign of 
orthobiosis. He spent the whole winter in researches 
on the intestinal flora and on the completion of his 
studies on infantile cholera. 

In the spring, on the occasion of his anniversary, 
he wrote the following : 

SfcVBBS, l&th May 1914. 

I have to-day entered my 70th year ; it is a great event 
for me. As I analyse my feelings, I realise more and more 
the weakening of my " life-instinct." 

In order to verify my impressions, I wished to hear again 


the musical compositions which formerly used to make me 
shed tears of enthusiasm (for instance, Beethoven's 7th 
Symphony or Bach's aria for the violin). Well, my impres- 
sionability towards music has very much lessened. In spite 
of the facility with which old people weep, I hardly shed a 
single tear, save with rare exceptions. 

I observe the same change in other circumstances. 

This spring, the blossoming of flowers, buds, bushes, and 
trees, all this renascence of nature, has not excited in me a 
shadow of the emotion of preceding years. 

Rather I felt a melancholy, not on account of my coming 
end, but because of the consciousness of the burden of existence. 

There is no question for me now of the old joy of living ; 
my predominant feeling is infinite anxiety for the health and 
happiness of those I love. I now so well understand Petten- 
koffer, who committed suicide at 84 after losing all his 
family. Their death had evidently been precocious because 
of the impotence of medicine. At every step, one comes 
across cases where neither hygiene nor therapeutics can do 
anything. How many are infected with tuberculosis, no 
one knows how or where. What is to be done to avoid it ? 
And the consequences of measles, of scarlet fever, perhaps of 
a simple sore throat, followed sometimes by tuberculosis 
or nephritis ! 

What is the use of being able to foretell, by means of the 
proportion of urea in the blood, the precise moment of the 
death of an " azotemic " patient when you cannot prevent it 
or cure him ? 

This imperfection of medical science prevents many 
from reaching true orthobiosis, and it is understandable that, 
seeing the present state of medicine, the feeling of the " burden 
of existence " may be precocious, as in my case. 

But it is indubitable that, in spite of the slowness with 
which medical science is developing, it will in the future 
reach a degree which will enable us to cease to tremble any 
longer before all sorts of incurable diseases. Orthobiosis will 
then appear, no longer under its present incomplete form, 
but as the solid and essential basis of life. 


Return to St. Leger-en-Yvelines Norka Studies on the death of the 
silk-worm moth War declared Mobilisation. 

THE drawback of the holidays consisted, for Metchni- 
koif, in coming away from his laboratory and in 
the impossibility of following his diet in a hotel or 
a boarding-house. We therefore resolved to hire a 
cottage in some quiet place, to organise a small 
laboratory, and to continue our usual mode of life. 

St. Leger-en-Yvelines, where we had spent part of 
the preceding summer, answered all our requirements. 
We took a small villa there and called it " Norka," 
which means in Russian " little hole," " little refuge," 
and came there for the holidays in July 1914. 

Elie seemed pleased to be there ; thanks to the 
laboratory, he could easily vary his occupations, for 
continuous reading fatigued him. His reflections 
having led him to the problem of natural death, he 
had for some time been seeking for a subject on which 
he could study the mechanism of the phenomenon. 
He had formerly studied the May-flies (Ephemeridse), 
predestined to a natural death by their rudimentary 
buccal organs, incapable of use in feeding. But 
the life of those insects, a life of a few hours or a 
few days at the most, was too short to allow the 
necessary researches. The males of the Rotifera, 
which are also deprived of buccal organs and even of 



digestive organs, were too small in size for physio- 
logical experiments. Thus, those two examples of 
natural death among multicellular beings were un- 
suitable to the projected study. 

He found a more favourable subject in the moth 
of the silk-worm (Bombyx mori) ; the rudimentary 
buccal organs of that insect make all feeding im- 
possible and predestine it to a natural death. The 
dimensions of the silk-worm moth are large enough 
and it has a life duration of twenty-five or thirty 
days, therefore sufficient to allow the study of the 
mechanism by which its death is brought about. 
Metchnikoff procured a quantity of silk-worms, and 
soon the moths hatched and covered all the mantel- 
pieces and tables in Norka with white flakes. He 
ascertained that it was not hunger which brought 
about the death of the moths, for their organism was 
not in the least exhausted. 

The nutrition of the latter takes place at the 
expense of the fatty substance which remains after 
the metamorphosis of the chrysalis into a moth. The 
dissolution of this fatty substance produces toxins 
which pass into the urine. Thus the obvious cause 
of the death of the moth is an acid intoxication by 
toxic urine secreted in the bladder. As the latter 
does not empty itself, uraemia becomes inevitable. 

The majority of moths contain no micro-organisms 
which could suggest death by infection. 

The only theoretic objection against a natural 
death might consist in the existence of " invisible 
microbes." Indeed, the question of invisible microbes 
revealed in certain infections perturbed Metchnikoff's 
mind to such an extent that, during his last illness, he 
used to say that it would have been a curse to his 


ulterior activity, a sort of ghost preventing all definite 
conclusions in problems connected with the absence 
or presence of microbes. The last word oh natural 
death, he said, will only be spoken when, owing to 
the improvement of the microscope, those microbes 
which are as yet invisible to us will become visible. 
Nevertheless, as far as can be judged at present, the 
death of the Bombyx mori is due, not to external 
causes, but to the structure of the insect itself, and is 
therefore a natural death. 

During these holidays, Metchnikofi also wrote 
reminiscences of his friend the physiologist Setche- 
noff. 1 

We went quietly for fairly long walks ; Metchni- 
kofi rested on the shores of his favourite lake (Vilpert), 
and his health was very satisfactory. 

After the intense heat, some rain came and the 
weather became ideal ; there was a perceptible 
lull in nature ; the underwood was becoming purple 
with heather ; the corn was ripening ; harvest had 
begun, and sheaves stood up in the fields. All was 
calm and peaceful ; we never tired of the charm 
of the forest, of the fields, of the beautiful rustic 
surroundings, and our souls sang in unison with 
Nature. . . . 

Suddenly, like a flash of lightning in the pure sky, 
the news of the war burst out ! 

The possibility had so often been mentioned in 
late years that no one believed in it. Even now, on 
the eve of the catastrophe, it was hoped that all 
would settle down. . . . 

Until the last moment Metchnikoff refused to 
believe in it ; he could not admit that a pacific 

1 In the Russian Review, Messenger of Europe. 


solution was impossible. "How is it possible that 
in Europe, in a civilised country, mutual interests 
should not be reconciled without killing ? " he said. 
" A war would be madness, even from the point of 
view of Germany, who risks having to face three 
great powers. No, war is not possible." 

And yet war was spreading all over Europe. 

The situation of France seemed critical, for the 
country had just gone through a series of internal 
storms. The labour question, that of income tax, 
and that of the three years' military service had 
raised sharp controversies ; the Caillaux affair had 
revealed hidden sores in political life ; the insane 
assassination of Jaures, of which the reason was 
still unknown, gave rise to the blackest prognostica- 

Already on the 28th July, date of the declaration 
of war by Austria against Serbia, anxiety had become 
intense, but it was hoped that Russia would settle 
matters between the two countries, and that the 
trouble would remain local. 

On the 1st August, Germany declared war on 
Russia, and it became obvious that the storm was 
coming on apace. The aspect of life suddenly 
changed; a feeling of dread and expectancy un- 
nerved everybody ; mobilisation was mentioned ; 
automobiles at full speed hurried along the roads ; 
the harvest was hastily gathered. . . . We could 
no longer work, go for walks, or admire nature with- 
out a feeling of heavy anxiety. 

We went about like automatons, all our thoughts 
centred on one point the threatening, inevitable 
war. Everything had put on a sinister aspect, and 
Nature herself joined in the general gloom ; the 


weather became stormy, thunder rolled alarmingly, 
heavy clouds hurried and met in a gigantic struggle, 
evoking the image of other coming struggles. During 
the night of the 1st August the storm never ceased, 
we could not sleep ; all night long, frenzied auto- 
mobiles raced along the high road, sounding their 
lugubrious horns. In the middle of the night, we 
heard some one knocking at the doors of the police 
station opposite. What was happening ? In the 
darkness, illumined by flashes of lightning, we saw 
horsemen with lanterns ; they were messengers 
bringing the orders for mobilisation. It was pro- 
claimed the next day. 

The population gathered at the mairie, a grave, 
silent crowd ; the few words exchanged only con- 
cerned war and partings. Old men, who had lived 
through 1870, were low-spirited ; young ones, on the 
contrary, were excited. 

We had to think of our return home, which might 
be difficult later. We went into the forest for the 
last time ; the evening was mild and calm after the 
storm. The peace and beauty around us were such 
that we longed not to believe in the terrible reality. 
But we had to bid farewell to all that had charmed 
us. We went once again into the meadows near 
Norka. The hayricks were standing in rows, their 
soft, golden silhouettes harmoniously outlined against 
the hilly background purple with heather. We sat 
down on the mown grass. Suddenly, in the calm of 
the evening, bells began to sound. It was not the 
distant and poetic call for vespers, nor the sad sound 
of the passing bell, but the hard, sinister, ill- 
omened tocsin, warning the whole countryside, down 
to the most distant, most peaceful hamlets and to the 



wood-cutters in the forest, that mobilisation had 
commenced. . . . 

Another storm broke out in the night. Again the 
rolling of the thunder shook our nerves and seemed 
like the echo of distant battles ; again mysterious 
automobiles and horsemen raced along the road, and 
eveiything, every sound, every shadow seemed 

We did not feel any fear, but a kind of insupport- 
able nervous tension. Later, when we were much 
nearer real danger, we did not experience this electric, 
almost morbid feeling. 

The next day, Germany had declared war on 

It was only with much difficulty that we found 
a carriage to take us to the station. On the road 
we were constantly being passed by various vehicles, 
crowded with soldiers and young men going off. The 
little station was full of people, the train also. Moved 
and excited, the people shouted, " Vive la France ! " 
and sent friendly salutes to unknown soldiers in the 
train. Women, seeing their men off, were trying to 
be gay ; they encouraged the departing ones, and 
only wept after they were gone. The general im- 
pression, both moral and material, was excellent ; 
every one seemed equal to his task, conscious of 
his duty, and desirous of fulfilling it well. The 
mobilisation seemed well organised, everything was 
being accomplished without any flurry or bustle, 
even the trains were almost punctual. 

All small personal interests and party quarrels 
which had latterly poisoned life now suddenly dis- 
appeared ; everywhere the desire to be useful was 
noticeable ; people became better, there was more 


sympathy, more solidarity; the distance between 
classes seemed to decrease, the common trial made 
all equal. 

There was beauty in that moment, for it showed 
that the greatest of evils might yet exalt and purify 
the human soul. 


Return to Paris The deserted Institute Memoir on the Founders of 
Modern Medicine Metchnikoff's Jubilee Last holidays at Norka. 

THIS was but the beginning of the war ; soon it 
spread with vertiginous rapidity, and made its cruel 
destructive force felt. 

On our return from Norka, we found every- 
thing on a war footing. The very next morning, 
Metchnikoff hurried to the laboratory. He only 
reached Paris with some difficulty, all means of 
communication being encumbered by soldiers. He 
had left the house nervous and excited but full of 
courage and energy. I shall never forget his return 
home. . . . 

I was awaiting him as usual, just outside the 
station, and, as he got out of the train, I did not 
recognise him. I saw a stooping old man, bent as 
under a heavy burden ; his usual vivacity was gone, 
and had given place to the deepest depression. 

He ibid me in a broken voice that the Institute 
was already deserted ; that it was under the orders of 
the military authorities, and completely disorganised 
for scientific work. The younger men were mobilised ; 
the laboratories empty ; the animals used for ex- 
periments had been killed on account of the departure 
of the servants, and for fear of a lack of food. Every- 
thing that had been devoted to the service of science 



and of research into means of preserving life had 
been handed over to the service of war. Normal and 
cultured life was arrested. And that was the out- 
come of civilisation. 

Metchnikoff felt as if he had suddenly been dropped 
into the abyss of centuries, into the times of human 
savagery. He could not accustom his mind to the 
idea of such a fall ; it seemed to him a paradox, an 
impossibility, that civilised peoples could not do 
without sanguinary fights in order to solve questions 
of mutual relations. 

The events which were taking place agitated and 
depressed him all the more that he had not the 
possibility of becoming absorbed in scientific investiga- 
tions ; he was completely thrown off his balance. 

And as, one by one, the news came of the death 
in action of several of the young men who had left 
the Institute, Metchnikoff's grief knew no limits. He 
could not bear the idea, now a terrible reality, that 
these brilliant young lives should be sacrificed, 
victims of those who should have directed the peoples 
towards peace and a rational life, and who, instead of 
that, threw the most precious part of humanity into 
the abyss of death. War became a dark, sinister 
background to his daily life. The victims of war 
were not only those who fell on the battle-field, but 
included him whose whole life -effort had been 
directed towards the conservation of human exist- 
ence and the search for rational conceptions. The 
contrast between his aspirations and the cruel reality 
had been to him a blow which his sensitive and suffer- 
ing heart was not fit to bear. 

The Germans were advancing rapidly. Then 
came the sad days of panic, when the inhabitants 


were leaving Paris in numbers and the Government 
started for Bordeaux. At night, the sky was swept 
by the gigantic, luminous sword of the searchlights ; 
the rumble of camion could be heard in the dis- 
tance. . . . 

Metchnikoff, however, had no personal fear what- 
ever. He very simply decided on his course of 
action, which was to remain at the Institute if his 
presence there could be of use ; if not, to retire to some 
quiet place where he could work. As there was 
hardly any staff left at the Institute on account of 
the mobilisation, he did not go away, but, on the 
contrary, we came to live in Paris, the communica- 
tion with Sevres being very difficult. 

The day we arrived was that on which the first 
German aeroplanes appeared, and they dropped bombs 
near the St. Lazare station just as we were alight- 
ing from the train. For some time after that, they 
carried out a raid above Paris every Sunday. 

In spite of the disorganisation of his whole life, 
Metchnikoff had succeeded in resuming his work to a 
certain extent. He took advantage of an oppor- 
tunity to observe an old dog who was suffering from 
diabetes, and hastened to examine his organs as soon 
as he died, whilst they were still fresh. He had for 
some time supposed that diabetes might be an in- 
fectious disease ; yet he was unable to discover any 
specific microbe either in the humors or in the organs 
of the dog. But he succeeded in provoking symp- 
toms of the disease (traces of sugar in the urine) in a 
healthy dog, by inoculating him with the pancreatic 
gland of the diabetic dog. He was much encouraged 
by this result, and would have liked to continue 
his researches, but was unable to do so because 


of the general disorganisation and the impossibility 
of obtaining animals for experiments. He had to 
content himself with continuing his memoir on 
infantile cholera and his observations on the silk- 
worm moth. 

As he was almost altogether precluded from 
laboratory work, he began to write a study on " The 
Founders of Modern Medicine," in order to demon- 
strate, by concrete examples, the importance of 
positive science in its application to life. This is 
what he said in his preface to the book : 

These pages were written under special circumstances. If 
not in the actual hearing of guns, it was in expectation of it 
that I had to spend several weeks in my Paris laboratory, 
now under war conditions. These meant an almost complete 
cessation of any scientific activity in our Institute. 

For fear of a lack of food, the animals used for our experi- 
ments had been killed, which deprived us of the possibility 
of proceeding with our researches. 

The stables of the Institute were filled with cows who 
provided milk for the hospitals and children's homes. 

The greater number of our young collaborators, assistants, 
or laboratory attendants were mobilised, and only the female 
employees and old men remained. One of the latter, I 
found myself in the impossibility of pursuing my investiga- 
tions and in possession of much leisure. I made use of it to 
write this book in the hope that it might be helpful. 

It is not intended for physicians, for they know all that is 
expounded in it, but for young men who are seeking a scope 
for their activities. 

We may be sure that the insane war which broke out in 
consequence of the lack of knowledge or of power of those 
who should have watched over peace, will be followed by a 
long period of calm. It is to be hoped that this unexampled 
butchery will, for a long tune, do away with the desire for 
fighting, and that soon the need will be felt of a more rational 


activity. Let those who will have preserved the combative 
instinct direct it towards a struggle, not against human beings, 
but against the innumerable microbes, visible or invisible, 
which threaten us on all sides and prevent us from accom- 
plishing the normal and complete cycle of our existence. 

The results acquired by the progress of the new medical 
science allow us to hope that, in a more or less distant future, 
humanity will be freed from the principal diseases which 
oppress it. 

After describing the state of medical science before 
Pasteur, Lister, and Koch, MetchnikofE compared 
with it modern medicine, created by these three 
Founders, and showed the great horizons opened by 
them to the medicine of the future. 

On the 26th of September 1914, whilst we were still 
in Paris, he had, in the laboratory, an attack of tachy- 
cardia, which lasted three hours but was much less 
violent than that of the year before. The winter, 
however, passed fairly well in spite of the emotions 
and continuous excitement caused by the war, and he 
had no other attack until April 1915, when again he 
had a slight tachycardiac crisis of a short duration. 
Yet he was very much changed : his hair was much 
whiter, his movements were slow, and his figure bent. 
His infectious gaiety and vivacity had disappeared, 
but he remained energetic and enthusiastic in his 
work, and gained more and more in serenity. 

Little children in the street called him " Father 
Christmas," and came confidingly to ask him for 
presents. They knew him well, and were aware that 
his pockets were always filled with sweets for them. 
He used to say that his growing love for children 
was the revelation of the grandfatherly instinct, for 
which he had reached the proper age. He especially 


loved one of his god-daughters, little Lili ; he had 
become attached to the child on account of her kind 
heart and exceptional sweetness, and also because, 
from the cradle, she had shown a marked preference 
for him. And yet his love for children was not to 
him a source of joy, for anxiety on their account pre- 
dominated over other feelings. 

In spite of the physical change which had super- 
vened, his brain continued to work untiringly as in 
the past, and he tackled new problems with youthful 
courage and boldness. He had planned a work on 
the sexual question, which, according to him, was 
treated erroneously, with the result that grave dis- 
harmonies occurred in human existence. 

Thus he reached some quite revolutionary con- 
clusions respecting education and marriage. He 
thought that morality should be set upon a quite 
different basis, new and rational ; and that was the 
question which he prepared to treat. 

The 16th of May of that year was his seventieth 

His satisfaction was great at having reached the 
normal limit, of age, for he saw in that a conclusive 
proof of the efficacy of his hygiene. Indeed, he 
showed on that day a sort of rejuvenation : his aspect 
was quite different, he was gay and animated as he 
had not been for a long time. 

The Pasteur Institute celebrated his jubilee. In 
spite of the absence from " The House " of many 
members on account of the war, the library filled with 
people, and the fete had a cordial and intimate 
character. Dr. Roux's speech 1 will remain the best 
description of E. Metchnikoff and of his scientific 

1 Annals de Vlnttitut Pasteur, Jubil6 d'E. Metchnikoff, 1915. 


activity. He himself responded to all those mani- 
festations of sympathy by a spirited speech, in which, 
a propos of his own particular case, he expounded his 
ideas on senility and the duration of life in general. 
This is what he wrote on that same day in his note- 
book : 

16th May 1915. To-day I have at last accomplished my 
seventy years ! I have attained the normal limit of life, a 
limit mentioned by King David and confirmed by the statisti- 
cal researches of Lexis and Bodio. 1 I am still capable of 
work and of reflection. But the changes in my psychical 
state which I had observed a year ago have become sensibly 
accentuated. The difference in acuteness both of pleasant 
and painful sensations is becoming more and more marked. 
Agreeable sensations are becoming weaker ; I am now in- 
different to many things which I used to appreciate very 

It is useless to say that I am indifferent to the quality of 
my food ; my need of musical impressions has become so 
much less that I hardly feel the desire to satisfy it. The 
charm of spring no longer touches me and only provokes 
sadness in my mind. 

On the other hand, my anxiety for the health and happiness 
of those I love is getting more and more acute. I find it 
difficult to understand how I ever could bear it. 

The powerlessness of medicine grieves me more and more, 
and, as a last straw, the war has interrupted all the work that 
had been undertaken against disease. In these conditions, it 
is not astonishing that I should feel a growing satiety with 
existence. Last year [16th May 1914 to 16th May 1915] I 
had two attacks of tachycardia, during which I should have 
been glad to die, but in general my health is satisfactory and 
that sustains me. What would have become of me if, to 
crown my misfortunes, I had fallen ill ! I certainly no longer 
fear death, but I desire to die suddenly during a heart attack 
and not to go through a long illness. 

1 Annales de I'Institut Pasteur, 1915. 


My comparative longevity is not due to family heredity 
(my father died in his 68th year, my mother in her 66th, my 
sister also, my eldest brother at 45, my second brother at 50, 
the third in his 57th year ; my grandparents I have not known). 
It is to my hygiene that I give the credit for having attained 
my 70 years in a satisfactory condition. I have taken no raw 
food for eighteen years and I introduce as many lactic bacilli 
as possible into my intestines. But it is but a first step ; in 
spite of all, I am being poisoned by the bacteria of butyric 
fermentation. However, I have practically reached the normal 
term of life and I must be satisfied. I have, so to speak, 
accomplished the program me of a " reduced orthobiosis." 

When macrobiotics become more perfect, when people have 
learnt how to cultivate a suitable flora in the intestines of 
children as soon as they are weaned from their mother's 
breast, the normal limit of life will be put much further back 
and may extend to twice my 70 years. Then, also, satiety 
with existence will appear much later than it has done in 
my case. 

To-day they celebrated my jubilee at the Pasteur Institute, 
which touched me very much, in spite of my distrust of senti- 
mental manifestations, for I realised their sincerity. I should 
have liked to set out a programme of the researches which 
should be accomplished by the Pasteur Institute, but I feared 
to detain my audience too long. 

I believe that Science will solve all the principal problems 
of Life and Death and that she will enable human beings to 
accomplish their vital cycle by real orthobiosis, not by a 
reduced caricature of it as in my case. Nevertheless, I con- 
sider the experiment practised upon myself as having already 
given some result and that is to me a real satisfaction. 

We spent that summer a few weeks at Norka, 
where Metchnikofl completed his researches con- 
cerning the death of the silk-worm moth. 

We went for delicious walks ; we spent all the 
afternoon by the lake or under the pines in the 
heather, reading and working. Once only, during a 


walk, lie had a strong cardiac intermittence, but as 
a rule he felt well. I could see, however, that he was 
obsessed by a grave preoccupation which he did not 
express. Later, during his last illness, he confessed 
to me that during the whole of that stay at St. Leger 
he had feared to die suddenly during one of our walks. 
The thought of my isolation weighed on his mind and 
he hid his anxiety so as not to alarm me. . . . 

With a view to the work which he had planned on 
the sexual question, he interested himself in the 
influence that their sentimental life had had on the 
activity of great men, and we read together the 
biographies of Beethoven, Mozart, and Wagner. 
Elie was more than ever desirous of making our 
holidays as pleasant as possible, as if he already felt 
that they were our last. Here are more extracts from 
his note-book : 

ST. LEGEB-EN-YVELINES, 24*A June 1916. 

When saying that I did not fear death, I had in view the 
dread of annihilation. That fear, manifested during a long 
period of life and disappearing towards the end, may be com- 
pared with the fear of darkness which children instinctively 
feel and which also disappears gradually and naturally. When, 
towards the end of life, the fear of nothingness ceases, no 
desire remains for a future life, for the immortality of the 
soul. It would even be painful to me to think that the soul, 
surviving the body, could watch, from beyond, the misfortunes 
of those who remain on the earth. On the contrary, towards 
life's decline, a desire for complete annihilation becomes 

He spent the autumn collecting and preparing 
the materials he required for his book on the sexual 
function. It was a relief from the sad impressions 
of the war and the deserted laboratory. But new 
troubles were in store for us ; I became ill, and had 


scarcely recovered when we heard the news of the 
death of a nephew who was very dear to us. The 
death of the young had always deeply moved Metchni- 
koff, and it was so in this case. It was another 
weight thrown into the already descending scale. 

In spite of all, he continued to work with enthusi- 
asm, planting young trees that future generations 
might enjoy their shade. 


Bronchial cold Aggravated cardiac symptoms Farewell to Sevres 
Return to the Institute Protracted sufferings Intellectual pre- 
occupations Observations on his own condition The end 

IF in this sad last chapter I occasionally dwell on 
details which may seem insignificant in themselves, 
it is because, at this supreme moment of Elie Metchni- 
koff's existence, everything was full of significance, for 
everything converged to emphasise the powerful 
unity and the ascending and continuous progress of 
his ideas. 

His attitude in the face of illness and death was a 
teaching, a support, and an example. That is why, 
relating the story of his last days, I piously describe 

Towards the end of November, he caught a slight 
cold, which did not prevent him from leading his 
usual life, but which, nevertheless, was the starting- 
point of the illness which took him from us. 

On the 2nd of December, during a walk, he suddenly 
felt a cardiac commotion such that he thought he 
was dying. For hours, his pulse remained inter- 
mittent and very rapid, and from that day he felt 
unwell but continued to go to the laboratory. 

On the 9th of December his condition became worse 
and forced him to interrupt his normal life. All the 
doctors were away or very busy on account of the war, 



and it was only on the 1 1th that Dr. Eenon could give 
him a consultation at the Laennec Hospital. He found 
Metchnikoff's heart very tired and nervous, prescribed a 
treatment, and told us to come back in twenty-five days. 

But the disease was making giant strides. In the 
night of the 12th to 13th a first attack of cardiac 
asthma supervened, an extremely painful one ; we 
had the impression that the end was near. Elie 
suffered agonies but remained morally calm and 
ready for death, as he had ever been since his first 
heart attack, two years previously. He repeated that 
he had accomplished his task and run through his 
vital cycle ; that what he could yet do would be but 
a supplement, and that it was better to die than to 
outlive his own decadence. 

He only wished not to suffer too long, but that 
humble desire was not to be realised. We spent two 
more nights at Sevres, terrible nights not to be 
forgotten if one had centuries to live, and we then 
decided to go to a nursing home in Paris, as it was 
imprudent to remain any longer isolated as we were. 

Having heard of Metchnikoff's illness, Dr. Koux 
offered to receive us at the Pasteur Institute in a 
small lodging which was now free, the house-physician 
who had occupied it having been killed. 

Dr. Widal, in whom Metchnikoff had absolute con- 
fidence, came to Sevres on the 14th and found myo- 
carditis. Thanks to an absolutely incomprehensible 
phenomenon, Elie had suddenly ceased to realise the 
rapidity of his pulse ; he had 160 beats in a minute 
and only perceived less than half ; it was therefore 
easy to keep the truth from him. 

After a last night of suffering we left our Sevres 
nest, which we had so loved. Leaning on my arm, 


he slowly walked through the little garden and gazed 
for the last time at the home that we were leaving 
for the unknown. . . . He looked worn and bent 
under the weight of suffering, but he was quite calm, 
and his eyes, though firm and gentle, already seemed 
to me to be looking very far away. 

The automobile bore us slowly from Sevres to the 
Pasteur Institute, and we found ourselves in the 
small flat which had been inhabited by the young 
doctor who had been killed in the war. He had only 
spent a short stage of his life there. How long should 
we remain ? And what road should we take when 
we left it ? We tried to smile, though our hearts 
were terribly heavy, in order to cheer each other. 

But, in the course of the day, we were surrounded 
by friends full of solicitude, the tension relaxed, and 
we felt a growing sense of comfort and security. No 
more nights of mortal dread and loneliness, with no 
help at hand ! That thought alone inspired courage 
and hope. In case of need, I had only to send down 
to the next floor to ask for a doctor. 

For a few days, Elie felt much better, perhaps on 
account of the mental relief, but his heart was weak 
and his pulse extremely rapid. Drs. Widal, Martin, 
Veillon, Salimbeni, and Darre came to see him every 
day ; during the whole of his long illness, they never 
ceased to show him the most attentive and devoted 
care. They attempted by every means to save him 
from pain, for, alas, they had no hope of curing him. 
Nothing was neglected, and many still greater suffer- 
ings were spared him. 1 

1 For instance, Dr. Widal, very early in his illness, had advised a saltless 
diet, which caused the infiltration in the tissues to remain comparatively 


The war was an inexhaustible and passionately 
interesting subject of conversation ; Elie read a 
number of newspapers and listened with avidity to 
every news from private sources. Often, too, scien- 
tific questions were discussed, which continued to 
interest him intensely. These talks were an in- 
valuable relaxation. 

Feeling infinitely grateful towards his medical 
advisers and friends, he showed himself a most docile 
patient, following their prescriptions with absolute 
punctuality. When his condition grew worse and 
he felt no hope whatever of his recovery, he often 
used to say, " What is to be done ? the doctors can 
do nothing, for medicine is powerless. Unhappily, 
it will remain so for a long time. Much work will 
have to be done to rid humanity of the scourge of 
diseases. But, surely, one day science will succeed 
in doing so ; that will be chiefly through prophylaxis 
and rational hygiene. There will also be a new 
science the science of death ; it will be known how 
to make it less hard." 

After lunch and a short sleep, he received the daily 
visit of his friend Dr. Roux, with whom he talked in 
the full intimacy of friendship and affection. He 
confided to him his apprehensions and desires, and 
felt unlimited gratitude for his kindness to us, often 
saying to me, with tears in his eyes, " I knew Roux 
was a kind man and a true friend, but I see now that 
he is incomparable." Other friends also did their 
utmost to serve him and to show their sympathy. 
He had the great joy of feeling himself beloved and 
surrounded with an atmosphere of real kindness. 
Many times he said to me, " Now, only, have I 
appreciated the warm-heartedness of the French 


at its full value. Do not fail, in my biography, to 
emphasise how deeply I feel it, and how grateful I 
am. I want them to know it." 

Yet all the care and devotion of which he was the 
object could neither arrest the fatal progress of disease 
nor spare cruel suffering to him' who had thought of 
nothing but relieving the pains of others. All our 
efforts were as flowers scattered over a tomb ; he, 
poor tortured one, was slowly, consciously sinking 
into it through the implacable logic of Fate. From 
the beginning of his illness, he foresaw the issue ; he 
lived in constant expectation of death, on the threshold 
of which his calm and serenity remained as unalter- 
able as were his patience and resignation. 

After a temporary and comparative lull, which 
lasted until the end of December, the disease began 
to progress again, and almost every week brought a 
fresh alarming symptom. It was especially during 
the night that the pain, treacherously, reappeared. 
After dropping asleep fairly early, he would begin to 
breathe with difficulty and then awake in an inde- 
scribable state of anguish ; perspiration drenched his 
head, neck, and chest, several towels often being 
required to dry him. His breathing was hard ; 
during bad attacks, the wheezing of his bronchial 
tubes was terrifying. 

He would sit up, his hands clenched, his face blue 
and contracted by suffering, his darkened lips apart, 
his eyes dilated the face of a man on the rack. He 
gasped like a suffocating man ; at last a tearing 
cough supervened, followed by expectoration, and 
the attack gradually subsided. 

For a time we were able to relieve him without the 
use of narcotics. As long as there was a ray of hope 


not of recovery, but of a bearable life and further 
work he wished at all costs to avoid the influence of 
narcosis. He breathed fumes of pyridin or ether, he 
smoked Escouflaire cigarettes, and inhaled various 
other things. In order to sleep after an attack, he 
ate a few biscuits, and I sprinkled his head with a 
menthol solution, with which I damped his temples 
and forehead. That eased him, and sometimes he 
slept again for a few hours. 

But how many were the nights of insomnia and 
suffering ! How many times did he call for death 
as a deliverer, and say that he resigned himself to 
live for my sake only ! 

And in spite of the martyrdom he endured, he 
always had gentle words, a caress, a consolation 
even ! He constantly returned to the thought that 
he had nothing to complain of, that he had had a 
large share of happiness and good fortune in having 
accomplished his task, and even arrived at the de- 
velopment of the natural death-instinct. 

All those who saw him every day knew that he 
was courageous and patient, every one admired his 
serenity, but no one could realise the degree of his 
courage and patience, for no one had seen and lived 
through those miserable nights. 

Often, even, when asked how he was, he said " not 
bad ! " after a terrible night, saying to me afterwards 
in explanation, " Why grieve them, since it cannot 
be helped ? " 

At the beginning of our stay in the Institute, he 
was not yet quite bedridden. After his morning 
toilet, he would lie for some hours on a sofa, reading 
almost continuously, newspapers, scientific reviews, 
and many works in connection with the book he had 


planned on the sexual function, of which he wrote 
only the introduction and a few lines of the first 
chapter. 1 

Another question occupied him at that time, that 
of first-born children. Certain data led him to think 
that men of genius were but rarely the first-born of 
their parents, and he sought for every possible 
information on the subject. In his constant desire 
to improve life-conditions, he even thought that a 
demonstration of this fact might have a desirable 
influence on the increase of population in France 
after the war ; if it were proved that the most success- 
ful children are not the first-born, perhaps the system 
of having two children only would be given up in 
order to have a chance of giving the country a more 
capable population. 

His reflections on the sexual questions led him to 
seek for experimental means of studying gonorrhoea. 
He thought of inoculating the gonococcus into the eye 
of new-born mice and entrusted M. Rubinstein, the 
only worker left in the laboratory, with these experi- 
ments. The latter began them and obtained en- 
couraging results, but he left Paris in the spring and 
the work remained unfinished. 

MetchnikofTs mind never ceased to. work unless 

1 He expounded the theory that ideas on the sexual function had been 
falsified through fear of venereal diseases at a time when people did not know 
either how to avoid or cure those diseases. He showed that the condem- 
nation of a natural function by divers religions was based on that fear. He 
analysed the deplorable consequences of that, and set forth the necessity of 
returning to more wholesome ideas, more in conformity with nature and 
allowing the study and avoidance of many evils. He thought that, in this 
connection, a new direction should be given to the education of children 
and to marriage. He then examined the part played by the sexual function 
in the lives of men of genius and, with that object, read many biographies 
and literary works. During his illness he read books concerning Victor 
Hugo and Napoleon, J. J. Rousseau's Confessions and even parts of the 
Nouvdle Heloise. 


interrupted by acute pain ; until the very end, his 
brain never failed him. He often used to say 
how far he was from any mystic aspirations, and 
how sure he was of remaining a rationalist 
until the end. And such was the case. Faithful 
to himself, not even in the most painful moments 
did he feel a desire to look for support outside 
the ideas and principles of his whole life. Yet 
his soul was sad and full of care ; the war grieved 
him utterly, every newspaper he read renewed his 
sorrow. When a severe engagement, Verdun for 
instance, was going on, he lost the little sleep he had, 
and his agitation became painful. 

He was deeply disillusioned by the Germans. 
Having always felt great esteem for their scientific 
work, he had believed in their high culture, and now 
he was absolutely disconcerted by the mentality 
which they manifested during the war. 

Neither could he understand how the war had 
been allowed to come about. He thought it ought 
to have been avoided, and considered the authorities 
guilty for not having done so. He said that nothing 
could compensate the harm done by this insane 

The deserted laboratories, the interruption of 
scientific work, filled his soul with melancholy. For, 
he said, all the great, all the real questions should 
have been solved by Science and were kept waiting. . . . 

He also had material worries, the war having 
brought great perturbation in his affairs. The fate 
of his mobilised pupils preoccupied him constantly. 
The least indisposition, however trifling, of those he 
loved made him unhappy. His sensibility, which had 
always been very marked, increased still more, and 


consumed him ; it surely was one of the causes that 
had worn his heart out. When already very weak 
and ill, he constantly thought of giving pleasure to 
those who were with him ; he read innumerable 
reviews and periodicals, and would tell each friend 
what he had found of particular interest to the latter, 
even when speech was difficult to him. His gentle- 
ness and cordiality were most touching during the 
whole of his illness, though he preserved his usual 
outspokenness. ... It seemed to me that this 
offended no one ; they all understood Elie now. 

He sought a refuge from his sufferings in his own 
ivory tower ; these sufferings themselves were to him 
a source of observations. He studied his body and 
his soul as he would have studied any subject under 
experiment. Every day he wrote down his auto- 
observations, and carefully read the diary which I 
kept for him. 

During the whole of the winter he had ups and 
downs. Towards the end of December the cough and 
respiratory symptoms increased, and at the beginning 
of January he expectorated clots of blood, due to 
a passive congestion of the right lung. 

On the 19th January, some liquid appeared in the 
pleura on the same side. Pleurisy persisted for a 
whole month and necessitated three punctures. 
Every time we feared to tell him that the puncture 
was necessary, but he received the news with com- 
plete coolness, saying that he had always been in 
favour of radical measures. 

After the third puncture, which took place on the 
19th February, a marked relief supervened, and the 
improvement lasted for some time ; it was the only 
moment when we saw a ray of hope. 


Though keeping to his bed, he worked a great deal, 
read, and received not only his friends but other 
visitors. At the beginning of March and at the end 
of April he again expectorated blood, and the terrible, 
tragical nights began again. Yet the days were 
fairly good. 

During that period, he had the pleasure of seeing 
some of his pupils again, and of receiving several 
Russian deputies and journalists. They talked to 
him of political events, of the war, of the moral state 
of Russia. All that interested him irnmp.Tisp.1y ; he 
plied them with the most varied questions. It must 
be remembered that, before that interview, we had 
lost all touch with Russia. 

During the whole of May he again had ups and 
downs, but the progress of the disease was indisput- 

Tachycardia was constant, urine more and more 
scanty, the swelling of the legs never decreased, cough 
and oppression occurred frequently even during the 
day. Elie awaited his seventy-first birthday with 
impatience. Often during the night, after a painful 
attack, he would count the days, hours, and minutes 
which separated him from that date. At last it 
arrived. Here are the lines which he added to his 
notes on that day : 

16th May. Against all expectation, I have lived until 
this day. I have reached my 71 years. My dream of a rapid 
death, without a long illness has not been realised. I have 
now been bedridden for five months. After several crises of 
tachycardia, following upon a slight grippe with asthma, I 
had congestion of one lung with pleuritic exudate. Though 
some improvement followed after that, nevertheless I am 
tormented by fits of sweating followed by cough and oppres- 


sion. I suffer chiefly in the night from those attacks ; 
they provoke insomnia which can only be combated by 

My psychical state is twofold. In one way, I should like 
to get well, but, on the other hand, I see no sense in living 
any longer. Illness has not provoked in me any fear of 
death, and I am more deprived than formerly of the joy of 
living. The reawakening of spring leaves me quite indifferent. 
There can be no question for me of that pleasure which con- 
valescents often feel, nor indeed of any pleasure. To the 
despair that I feel in the face of medicine's powerlessness to 
cure the ills of my friends is added the feeling of its powerless- 
ness towards my own illness. I think that my desire to re- 
cover and to continue to live is connected with practical 

The war has compromised our finances, our income from 
Russia has practically disappeared. If I die, my wife may 
find herself in a very difficult situation. Given her lack of 
practical notions, that may lead to very sad results. Yet it 
is quite impossible to straighten our affairs before the end of 
the war and the re-establishment of normal conditions. 

These were the last words he wrote in his book of 
notes ; his hand had become weak and trembling ; 
he tired very soon, and henceforth I wrote under his 
dictation. On the 18th June, one month before his 
cremation, he dictated to me for the last time, and 
this is what he said : 

This is the seventh month that I have been ill and it 
brings my thoughts back to the gravity of my condition. 
I therefore continually realise how much satisfaction I have 
derived from life during my long years. The gradual disap- 
pearance of my "life-instinct," which already began a few 
years ago, is now more marked, more precise. I no longer 
feel that degree of pleasure which I felt only a few years ago. 
My affection for my nearest and dearest shows itself much more 
by the anxiety and suffering provoked by their diseases and 


sorrows than by the pleasure I derive from their joys or 
normal health. 

Those to whom I describe my feelings tell me that satiety 
with living is not normal at my age. To that I oppose the 
following : Longevity, at least to a certain point, is hereditary. 
Now I have already mentioned, on the occasion of my 70th 
anniversary, that my parents, sister, and brothers died before 
reaching my present age. I knew neither of my grand- 
parents, which shows that they could not have been very old 
when they died. 

Let us now turn to the profession, since it is an established 
fact that it has an influence on the duration of life. Pasteur 
died at 72, but for a long time he had been unable to do 
scientific work. Koch did not reach the age of 67. Other 
bacteriologists died at a much earlier age than I (Duclaux, 
Nocard, Chamberland, Ehrlich, Buchner, Loeffler, Pfeifier, 
Carl Fraenkel, Emmerich, Escherich). 

Among those bacteriologists of my generation who are still 
living the majority have already ceased from working. All 
that should indicate that my scientific life is over and confirm 
at the same time the fact that my " orthobiosis " has actually 
reached the desirable limit. 

He was anxious to prove that his end, which 
seemed premature at first sight, did not contradict 
his theories, but had deep causes such as heredity 
and the belated introduction of a rational diet. He 
had only begun to follow it at fifty-three. Facts 
corroborated him after his death, for the post-mortem 
examination showed that the heart lesions were of 
long standing. He himself thought they went back 
at least to 1881, when he had had a very grave 
relapsing fever. The doctors even wondered how he 
had lived with his heart in such a state, and only 
accounted for it by the strict regime which he had 
followed during the latter part of his life. 

And indeed when it is remembered how pugna- 


cious, how vehement he was always, so to speak, 
in a state of ebullition, feverishly active, intensely 
sensitive it must be admitted that his life really 
held more than an ordinary life of longer duration. 

He was very desirous that the example of his 
serenity in the face of death should be encouraging 
and comforting. It should prove that, at the end of 
his vital cycle, man fears death no longer ; it has 
lost its sting for him. 

Early in June his condition became still worse. 
The nights were so painful that, every evening, recourse 
had to be had to pantopon. 1 It was with the greatest 
impatience that he awaited his " dear Darre and dear 
Salimbeni," as he called them. 

After Dr. Darre had finished his complete and 
thorough medical examination, we three remained 
talking around Elie's bed for a short hour. He often 
recalled his personal or scientific memories when he 
was not too weary ; we talked of the war, of medical 
questions ; often, too, we would evoke, with Salimbeni, 
recollections of our journey to the Kalmuk Steppes. 

We loved that peaceful hour, which ended by an 
injection of pantopon, the only relief, alas, that could 
be procured for him. He would thank Dr. Darre with 
gratitude, and drop his poor weary head on the pillow, 
awaiting in absolute security the blessed sensation of 
warm heaviness which pervaded him, for he knew 
that sleep and rest from his sufferings would not be 
long in coming. The spectre of tragical nights never 
ceased to haunt us. 

Until the hot weather came, he was quite com- 
fortable in the small flat in the Pasteur hospital ; the 
temperature there had been perfectly regular all 

1 Pantopon is a narcotic drug prepared from opium. 


through the winter ; but now he began to be incom- 
moded by the heat. 

M. Roux then proposed that we should be trans- 
ferred to Pasteur's old flat ; the rooms were spacious 
and much cooler. This idea rejoiced and touched 
Elie very much. As he thanked M. Roux, he said to 
him : " See how my life is bound with the Pasteur 
Institute. I have worked here for years ; I am 
nursed here during my illness ; in order to complete 
the connection I ought to be incinerated in the great 
oven where our dead animals are burnt, and my 
ashes could be kept in an urn in one of the cupboards 
in the library." " What a gruesome joke ! " answered 
M. Roux, really taking those words for a joke. But 
directly after he was gone Elie turned to me with an 
anxious look and said, " Well, what do you think of 
my idea ? " I saw by his earnest expression that he 
meant what he said, and I answered that I thought it 
a very good idea. The Pasteur Institute had become 
his refuge, the centre of all his scientific interests; 
he loved it ; he had spent his best years there. Let 
his ashes be laid there some day ; it would be in 
perfect harmony with his past. Let us only hope 
that would not be too soon ! But why had he given 
his words that jesting form which must have misled 
M. Roux ? He explained it to me : knowing how 
deeply conscientious his friend was, he did not wish 
to express his desire as a dying wish in order that he 
should feel no obligation. A simple jest, on the 
contrary, left him absolutely free. 

On the 26th June, Elie was carried into Pasteur's 
flat ; it was a very great satisfaction to him, it brought 
him nearer his laboratory. Now and then, very 
seldom now, he thought he might return there one 


day ; lie said I should wheel him there in his bath 
chair. " I know I could scarcely work there myself. 
But perhaps I might still play the part of a ferment, 
be useful to my pupils by giving them advice. I am 
leaving so much unfinished work which it would be 
interesting to go on with : the question of intestinal 
flora, that of diabetes, which surely is an infectious 
disease but that will have to be proved, and my 
experiments on the subject were scarcely begun. I 
think the study of gonorrhoea will give very interesting 
results when they succeed in inoculating it in new- 
born animals. And the question of tuberculosis is 
well started ! I could still help my pupils and en- 
courage them if I were a little better ! . . . But I 
have no illusions ! I must live now only from day 
to day. . . ." 

Those words were uttered with heart-rending 

He continued to get worse. . . . 

It was fortunate that pantopon should have given 
him good nights, for attacks of oppression now super- 
vened several times during the day ; tachycardia was 
continuous, the heart was weakening. The quantity 
of urine diminished ; it often did not surpass 250 cubic 
centimetres, and no diuretic succeeded in increasing 
it ; the legs remained swollen, ascitis was beginning to 
become visible ; in the night he occasionally grew 
slightly delirious. 

At the beginning of July he wished to sit up ; he 
spent part of the afternoon in an armchair, his legs 
lying on cushions. We thought it was a good sign, 
but in reality he found it difficult to breathe lying 
down. Several times he asked me to play to him, 
very soft music, as noisy sounds wearied him. I 


played Mm some Beethoven, some Mozart ; the last 
time it was a Chopin prelude. 

On the 9th his temperature went down in an 
alarming way to 35 '2 C. (95 F.). For the first time 
he would not write down his ordinary observations. 
" What is the good ? " said he, " it has no longer any 
interest." Yet the next day he did so, for the last 
time. On the llth and 12th he put down his tem- 
perature, and glanced superficially at the notes I 
had written. On the 12th, about five o'clock in the 
morning, he had a bad fit of breathlessness followed 
by coughing, and brought up large clots of very red 
blood. He smiled faintly. " You understand what 
that means," he said, adding some tender words. 

I wheeled him to his bed, which he never left again. 

On the 13th, in the early morning, he felt very ill. 
Calmly and gently he warned me to be ready. " It 
will surely be to-day or to-morrow." 

My heart breaking, I asked him why he said that ; 
was he feeling very weak ? or suffering very much ? 

" No," he said, " it is difficult to say what I feel ; 
I have never felt anything like it ; it is, so to speak, a 
death-sensation. . . . But I feel very calm, with no 
fear. You will hold my hand, will you not ? " 

How can I describe those last three days ? He 
preserved all his lucidity and serenity, often smiling 
at me and drawing me towards him. He inhaled 
oxygen very often, as breathlessness became almost 

On the 14th there was to be a matinee perform- 
ance of Manon Lescaut, and remembering that his 
god-children had long wished to see that opera, he 
had had a box taken for them. He was now quite 
uneasy about it. " What ill-luck," he said, "if it 


happened just before and prevented them from 
going. In any case they must not come here on 
their way to the theatre, so that if it happens they 
will not know, and can still enjoy the performance." 

Thanks to pantopon, he spent a very good night. 
He awoke about five o'clock, but remained so quiet 
that I thought him asleep. When I rose about six 
he held out his hand to me and told me he had been 
awake for a long time. He talked to me tenderly, in 
the full intimacy of our affection ; he spoke sweet, 
unforgettable words. He made me promise once 
again not to give way to grief. " At first, our friends 
will help you, and then work, that infallible remedy, 
and duty. . . . You will have that of writing my 
biography. Remember how much I wish the last 
chapter to be complete. You alone can write it, for 
you have seen me all the time ; I have told you all 
my thoughts, and yet ..." I understood that he 
had occasionally, out of pity for me, hidden his suffer- 
ings and his sad thoughts. But he did not know how 
often I guessed what he did not say ; love and pain 
have a dumb language, more eloquent than any 
human words. 

" You will hold my hand when the moment comes," 
he repeated. " But do not think I am afraid, now 
that it is near. No, I assure you, I have an absolute 
serenity of soul ! I spent a divine night. It seemed 
to me that I was already half outside life. This night 
has taught me many things. . . . Everything which 
troubled me, everything that seemed so disturbing, so 
terrible, like this war for instance, seems so transitory 
now, such a small thing by the side of the great 
problems of existence ! . . . Science will solve them 
some day." He ceased speaking. He seemed 


illumined by a very exalted feeling ; it was like the 
last chord of his harmonious soul. What a consolation 
if he could have died then ! 

But life is cruel. He lived through two more 
days of suffering. On the 14th he inhaled oxygen 
almost continually. He asked for pantopon, but we 
feared to give him too much. I told him it would 
induce such continuous sleep that he would not even 
be able to enjoy it. " But an eternal sleep is pre- 
cisely what I want ! Do understand that now 
nothing is left to me but pantopon. What is the 
good of making me last ? Is this a life ? A few 
days or a month have no importance when 
one is not going to recover. And you cannot 
wish to prolong my sufferings." His breathlessness 
increased ; he said, " Give me your hand ; stay near 
me ! " I knew what he meant ; he had the " death- 

His poor hands were hot and warmed my cold 
ones. . . . The next day I could not warm his hands, 
ice-cold for ever. 

The whole day he awaited with impatience the 
hour for pantopon. About nine o'clock, when Dr. 
Darre came in, he said, " Dear Darre, at last ! " 

There was no talk that evening, he was so weary. 
With what anguish I awaited the stroke of midnight, 
which ended those two dread days ! He had been 
mistaken by barely one day. The night was not bad, 
in spite of breathlessness and some fits of coughing. 
The next morning he felt better. He had not read 
the papers the day before, to-day I read him the com- 
muniques in the Petit Parisien, he said it was enough. 
He also turned the pages of a book he had recently 
begun to read, La Science et les Alkmands. 


I told him how pleased I was to see him better. 
" It is true," he said, " to-day I have no death- 
sensation, but I beg you, have no illusions ! " 

Always that preoccupation of breaking the shock 
for me. He made me bring a pocket-book with some 
money in it and a few envelopes ; in each of them he 
made me place notes of similar value, then with his 
already shaking hand, he himself wrote on each 
envelope the value of the notes multiplied by their 
number, and explained that it was to help me to find 
quickly what I should require after the catastrophe. 

He ate better at lunch than he had done lately ; but 
already at two o'clock the breathlessness increased. 
Yet he did not look pale ; he had preserved his 
rosy complexion. As he inhaled the oxygen, he was 
shaken by a hiccough. He pressed my hand. " It 
is the end," he said, " the death rattle ; that is 
how people die." He looked at his watch on the 
small table, it marked four o'clock. 

" No," he said, " it must have stopped. Four 
o'clock struck some time ago." And he smiled. 
" Is it not strange that it should have stopped before 
I ? Go and see what time it is." 

I ran out to see the clock from the window of 
another room ; it was twenty minutes to five. I met 
some one in the passage and asked him to go quickly 
to fetch one of the Institute doctors. Then I begged 
Elie not to have such ideas, and tried to cheer him. 

" But, my child, why do you want to calm me ? I 
am quite calm ; I am only stating facts," he said, 
adding tender words. 

At that moment Salimbeni came in. Elie said to 
him : " Salimbeni, you are a friend ; tell me, is it 
the end ? " And as he protested, he added^ " You 


remember your promise ? You will do my post- 
mortem ? and look at the intestines carefully, for I 
think there is something there now." MM. Roux and 
Martin then arrived. The feeling of weight in the 
intestines of which he complained was mentioned. 
He did not know that he had ascitis in the peritoneum. 

As I was attending to him I felt him move sud- 
denly, and said, " I beg you, do not make such sudden 
movements ; you know it is not good for you." He 
did not answer. I raised my head ; his was thrown 
back on the pillows, his face had assumed a blue 
tinge, the white of the eyes alone could be seen under 
the half -closed lids. 

Not a word, not a sound. 

All was over. 1 

Then an abyss of oblivion. . . . 

I saw him again, stretched on his deathbed. He 
was white, cold, and dumb. His face bore a calm 
and very serious expression. He looked like a 
martyr who had at last entered into rest. Death 
had marked his face with no dread seal. The lids 
had closed of their own accord, and he seemed to be 
sleeping after great lassitude ; one might have 
thought that, with his usual kindness, he wished to 
spare us all too painful an impression. . . . 

All through the night and the next morning his 
face preserved the same expression. 

In the afternoon Salimbeni performed the autopsy. 
Then he was laid in his coffin ; twenty-four hours had 
elapsed since the end. Wrapped in a white sheet, 
which framed his fine face, he had the appearance of 
a biblical prophet. 

Now his expression had assumed absolute serenity, 

1 It was 5.20 by the conventional war time, 4.20 in reality. 



illumined by gentleness and kindness. He had a look 
of elevation, grandeur, and beauty which was really 
divine. It was an apotheosis. His beautiful soul 
beamed in its full purity ; neither suffering nor any 
earthly preoccupation had any hold on it. He gave 
an impression of eternal rest. 

It was his final image, a splendid one, the last . . . 
for ever. 

The bier was closed and covered with a heavy 
black pall. On life also a blacker and heavier pall 
had fallen. The light had gone out. 

Two days later, on the 18th July, he was carried 
to the cemetery of the Pere Lachaise, to be cremated 
in all simplicity, as he had wished. Faithful to his 
ideas, he had wished for a lay funeral, with no speeches, 
flowers, or invitations. 

His bier disappeared into a large sarcophagus ; on 
each side black curtains fell to hide what was going 
on. . . . Then one hour of heavy silence whilst the 
poor body was being consumed by the flames. . . . 

A death silence. . . . 

And that was all. . . . 

The mercurial, vivacious child, good - hearted, 
intelligent, and precocious ; the young man, ardent, 
impetuous, passionate, a lover of science and of all 
that was exalted ; the mature man, a bold thinker, 
an indefatigable investigator, eager, generous, tender, 
and devoted ; the old man, in everything faith- 
ful to himself, but progressing in serenity, shining 
with an ever softer light, like a mountain peak in the 
setting sun ; the martyr at last, enduring suffering 
with patience and resignation, seeing the approach 
of death without fear, observing it as he had observed 
life. . 


The hour of silence was over ; the incineration 
accomplished. Of his body, little was left a handful 
of ashes. They were enclosed within an urn and 
placed in the library of the Pasteur Institute. 

But his beautiful, ardent soul, his audacious and 
fertile ideas, all that rich inner life which had 
developed into a harmonious and puissant sym- 
phony, all that cannot be dead, cannot disappear ! 
The ideas, the influence we give to life must persist, 
must live ; they are the sacred flame which we hand 
on to others and are eternal. 


THE life and work of Elie MetchnikofE are so inti- 
mately bound together that, in a biography, it is im- 
possible to separate them. That is why the descrip- 
tion of his work necessarily has been dispersed along 
the story of his life ; but, just as, in order to judge of a 
work of art, one has to draw back and contemplate 
the whole, we must also, after following the evolution 
and successive stages of E. Metchnikoff's scientific 
works, take a full view of his work as a whole. 

He was a born biologist ; everything connected 
with life interested him. In his childhood, he ob- 
served plants and animals. At the age of fifteen, he 
became acquainted with microscopic beings ; they 
aroused in him such powerful interest towards the 
primitive forms of life that, from that moment, not 
only his future path was marked out for him but also 
his method of starting from the simple to elucidate the 
complex. He was imbued with Darwin's theory 
of evolution ; having begun by the study of inferior 
animals, he began to look for their connections with 
other groups. 

He endeavoured to establish the continuity and 
the unity of phenomena in all living beings. Accord- 
ing to his method of studying first what was simplest, 
he turned to embryology, for in the egg and the 
embryo it is possible to follow step by step the trans- 



formation of the simple to the complex and to see the 
origin and development of all the constituent parts 
of the organism. Moreover, the embryo is exempt 
from secondary complications, due to the multiple 
external conditions of post-embryonic life. 

Metchnikoff was able to establish, from embryo- 
logical data, that the development of lower animals 
takes place according to the same plan and under 
the same laws as that of higher animals. In all of 
them, the segmentation of the egg is followed by the 
formation of embryonic layers, of which each gives 
birth to cells and to definite organs. Superior forms 
repeat, in their embryonic life, the evolution cycle of 
inferior forms. 1 

This common plan in the embryology of all 
animals established their genealogical continuity and 
strengthened the Darwinian theory. 

Metchnikofi's studies, carried out on the various 
groups of animals, contributed towards the founda- 
tion of comparative embryology. Owing to the 
comparative method, he had made himself familiar 
not only with the morphological and functional con- 
tinuity of divers organisms, but also with that of 
their constituting cells ; a comparison between the 
latter and unicellular beings was inevitable. That is 
why, having ascertained that the mobile cells of the 
lower Metazoa absorbed foreign bodies by inclusion, 
he naturally concluded that that phenomenon was 
similar to digestion in unicellular beings. 

Having established the fact of intracellular diges- 
tion in lower animals, he extended it to certain cells 

1 Thus the parenchymella, phagocytdla, and gastrula stages correspond 
in the embryo with the adult form of certain very primitive Metazoa and 
even to a colony of unicellular animals. 


of the higher animals ; thus his phagocyte theory 
was born. 

Seeing that unicellular beings, like the mobile cells 
of Metazoa, englobe, not only food, but foreign 
bodies, he asked himself whether this was not at 
the same time a defensive action. Such a possi- 
bility brought no surprise to a zoologist, accustomed 
to see that, in the struggle for existence, animals 
often devoured their enemies. 

All the materials for the building up of the phago- 
cyte theory were therefore ready in MetchnikofFs 
mind when he asked himself, as by an intuition, 
whether the white globules of our blood, globules 
so similar to amoebae, do not play the part of a 
defensive army in our organism when they envelope 
in accumulated masses intrusive bodies injurious to 
the organism. 

The thought was but the result of a preparatory 
work already accomplished ; it was the butterfly 
escaping out of the chrysalis. 

MetchnikofE had recourse to his method of simpli- 
fication in order to solve the question. 

The organism of the higher animals being ex- 
tremely complicated, he went down as far as the 
transparent larva of the starfish (bipinnaria) in order 
to watch with his own eyes the phenomena which 
take place within it. He introduced a rose-thorn 
into the transparent body of the larva, and noted 
the next day that the mobile cells in the latter had 
crowded towards the splinter, like an army rushing 
to meet a foe. 

The analogy of this phenomenon with inflamma- 
tion and the formation of an abscess was striking. 
Metchnikoff said to himself that since most diseases 


in the higher animals are accompanied by inflam- 
mation and provoked by microbes, it was chiefly 
against these microbes that our defensive cells had 
to struggle. He named the defensive cells phagocytes. 

He confirmed his hypothesis by another observa- 
tion, equally simple. In a little transparent crusta- 
cean (Daphnia) infected by a small parasitic fungus, 
(Monospora bicuspidata), he was easily able to 
observe the struggle between the animal's mobile cells 
and its parasites. 

These two simple observations served as founda- 
tion and supports to the bridge by which Metchnikoff 
connected normal biology with pathological biology. 
Having entered the domain of the latter, he studied 
various microbian diseases, and asked himself why 
the organism was sometimes liable and sometimes 
refractory. In order to elucidate this question, he 
turned again to lower animals, in which he could easily 
observe the most intimate phenomena, simplified. 

He ascertained that liability in an animal corre- 
sponded with the fact that microbes introduced into 
the organism remained free and invaded it, whilst 
immunity coincided with the inclusion and digestion 
of the microbes by phagocytes. 

He also found that, in artificial immunity, the 
phagocytes are accustomed gradually, by preventive 
inoculations, to digest microbes and their toxins. 

Thus he established the fact that phagocytosis 
and inflammation are curative means employed by 
the organism. 

All his ulterior researches, his studies on the 
various categories of phagocytes and their properties, 
on their digestive liquids, on the formation of anti- 
toxins, on the different properties acquired by the 


blood, etc., were but the natural development of 
those premises. 

He had proved that the part played by the phago- 
cytes consists, not only in the struggle against microbes 
and their poisons, but also in the destruction of all 
the mortified or enfeebled cells of the organism, and 
that atrophies are nothing more than the absorption 
of cellular elements by the phagocytes. 

He found that senile atrophies have the same 
cause, and asked why the cells of old people's 
organisms should become enfeebled. 

He demonstrated that the principal cause is the 
chronic poisoning of the cells by toxins manufactured 
by microbes in the intestine. Premature senility was 
the result a phenomenon as pathological as any 

The source of the evil, therefore, resides in the 
intestinal flora. Accordingly he started to study the 
latter, as also senility, in order to find means of 
struggling against both. 

His researches enabled him to indicate a series of 
means, based, on the one hand, on the struggle against 
microbes, and, on the other, on the defence of the 
noble cells against destructive ones. 1 

The study of old age led him to that of syphilis, 
a disease which provokes an arterio-sclerosis which is 
similar to that of old people ; the study of the normal 
intestinal flora was followed by that of intestinal 
diseases, such as typhoid fever and infantile cholera. 

Finally, he progressed towards the last pheno- 
menon, the most mysterious in nature, Death. 

1 Replacement of the wild and noxious flora of the intestines by 
antagonistic cultivated microbes ; strengthening and vaccinating of noble 


Researches on the silk-worm moth a rare ex- 
ample of an animal the life of which ends in natural 
death allowed him to conclude that the latter is 
due to an auto-intoxication of the organism. 

But he only just raised the veil of the great 
mystery ; it was his last work. . . . 

Metchnikofl's philosophical evolution ran on 
parallel lines with his scientific researches. 

When studying the laws and the unity of vital 
phenomena he found that their harmony was occa- 
sionally broken by the collision of internal conditions 
with the environment and that regrettable conse- 
quences ensued. He saw an example of that in human 
nature, full of disharmonies due to its animal origin. 

These considerations caused the pessimism of his 
youth. But his energetic, pugnacious temperament 
could not remain content with a passive acceptance 
of facts. 

He started to study the lack of harmony in human 
nature and its causes, and sought for means to combat 
these causes. Gradually he reached the conclusion 
that the greatest human disharmonies are provoked 
by the rupture of the normal cycle of our life, by the 
precocity of senility and of death, chiefly arising from a 
chronic poisoning by the toxins of intestinal microbes. 

But having acquired the conviction that it is 
possible to struggle against that intoxication, he con- 
cluded that science, which has already done so much 
to fight diseases, would also find means of struggling 
against premature old age and 'precocious death, thus 
leading us to the normal vital cycle, orthobiosis. 

Then disharmony, transformed into harmony, will 
cause the greatest of ills to disappear. 


Faith in the power of Science and in the possibility 
of modifying human nature itself through Science 
was the foundation of the optimistic philosophy of his 
maturity. Thoughts full of strength and hope shine 
like leading stars all along his philosophical works. 

" Alone, Kational Science is capable of showing 
humanity the true path." 

" The real goal of human existence consists in an 
active life in conformity with individual capacity ; 
in a life prolonged until the appearance of the death- 
instinct, and until Man, satisfied with the duration of 
his existence, feels the desire for annihilation." 

" Man is capable of great works ; that is why it 
is desirable that he should modify human nature and 
transform its disharmonies into harmonies." 

"If an ideal capable of uniting men in a sort of 
religion is possible, it can only be founded on scientific 
principles. And, if it is true, as is often affirmed, 
that man cannot live without faith, it must be faith 
in the power of Science." 

Thus Elie Metchnikofi had begun by the study of 
nascent life in inferior beings ; by a logical and con- 
tinuous chain, he had followed the whole cycle of 
development of living beings in their continuity and 
their whole. 

From the initial question of intracellular digestion 
he had reached the most exalted problems which can 
occupy our minds, the harmonising of human dis- 
cords through knowledge and will. 

Such is the harmonious edifice which he has 

No vital question was indifferent to him. He 
tackled the most difficult and most mysterious among 
them with courage, moved by an invincible impulse 


towards Truth and sustained by enthusiasm and 
faith in the power of Science. 

The beauty of a work of art consists in the harmony 
and unity of a realised conception. 

Thus a Gothic cathedral, by its graceful and har- 
monious lines, expresses an impulse towards higher 
spheres; it leans solidly on the earth only in order 
to soar better towards the heavens. 

Such is also the character of Elie Metchnikofi's life- 



1865. " Beitrage zur Kenntniss der Chaetopoden," Zeitschrift fiir wissen- 

schaftliche Zoologie, xv. 3, p. 328. 
" Uber einige wenig bekannte Thierformen," Zeit. f. wissen. Zool. 

xv. 4, p. 450. 
" Uber Geodesmus bilineatus Nob. (Fasciola terrestris), eine euro- 

paische Landplanarie, Melanges biologiques " (Bull, de 1' Academic 

des Sciences de Saint-Petersbourg, vol. v.). 

1866. " Untersuchungen iiber die Embryologie der Hemipteren (vorlaufige 

Mitteilung)," Zeit. f. wissen. Zool. xvi. 1, p. 128. 
" Zur Entwicklungsgeschichte von Myzostomum," Zeit. f. wissen. 

Zool. xvi. 1, p. 326. 
" Apsilus lentiformis, ein Raderthier," Zeit. f. wissen. Zool. xvi. 3, 

p. 1. 
" Embryologischen Studien an Insecten," Zeit. f. wissen. Zool. xvi. 

Entgegnung auf die Erwiederung des Her. Prof. Leuckart in 

Giessen, in Betreff der Frage iiber die Nematodenentwicklung 

(Gottingen, Verlag von Adalbert Rente). 

1867. " Beitrage zur Naturgeschichte der Wiirme," Zeit. f. wissen. Zool. 

xvii. 4, p. 539. 

"Embryology of the Sepiola" (in Russian), Archives des Sciences 
physiques et naturelles, Geneve, vol. 21. 

1868. " Beitrage zur Kenntniss der Entwicklungsgeschichte der Chae- 

topoden " (in collaboration with Ed. Claparede), Zeit. f. wissen. 
Zool. xviii. 

1869. "Embryology of Nebalia" (in Russian), Melanges biologiques de 

l'Acad6mie de Saint-P6tersbourg, vi. p. 730. 
"Untersuchungen fiber die Metamorphose einiger Seethiere, 

Tornaria," Zeit. f. wissen. Zool. xx. p. 131. 
"Uber ein Larvenstadium von Euphausia," Zeit. f. wissen. Zool. 

xix. 4, p. 179. 
" Uber die Entwicklung der Echinodermen und Nemertinen," 

Memoires de 1'Acad. de Saint-P6tersbourg, xiv. 8, p. 33. 

1870. " Bemerkungen iiber Echinodermen," Bulletins de 1'Acad. de 

Saint-Petersbourg, xiv. p. 51. 
" Embryologie des Scorpions," Zeitschr. f. wissen. Zool. xxi. 

1871. "Uber die Metamorphose einiger Seethiere," Zeit. f. wissen. Zool. 

xxi. 2, p. 235. 


" Entwioklungsgeschichte des Chelifers," Zeit. f. wissen. Zool. xxi. 

p. 513. 

" tlber den Naupliuszustand von Euphausia," ibid. Bd. xix. 
1872. " Zur Entwioklungsgeschichte dor einfachen Ascidien," Zeit. f. 

wissen. Zool. xxii. 3, p. 339. 
" Vorlaufige Mitteilung iiber die Embryologie der Polydesmiden," 

Melanges biologiques des Bullet, de 1'Academie des Sciences 

de Saint-Petersbourg, vol. viii. 
" Zur Entwicklungsgeschichte der Kalkschwamme," Zeit. f. wissen. 

Zool. xxiv. p. 1. 
" Studien iiber die Entwicklung der Medusen und Siphonophoren," 

Zeit. f. wissen. Zool. xxiv. p. 15. 
" Embryologie der doppelfiissigen Myriapoden," Zeit. f. wissen. 

Zool. xxiv. p. 253. 
1874. " Embryologisches iiber Geophilus," Zeit. f. wissen. Zool. xxv. 

p. 313. 
1876. "Beitrage zur Morphologic der Spongien," Zeit. f. wissen. Zool. 

xxvii. p. 275. 

1878. " Spongiologische Studien," Zeit. f. wissen. Zool. xxxii. p. 


1879. " Spongiologische Studien," Zeit. f. wissen. Zool. xxxii. p. 374. 

1880. " t)ber die intracellulare Verdauung bei Coelenteraten," Zoologischer 

Anzeiger, No. 56, p. 261. 
" Untersnchungen iiber Orthonectiden," Zeit. f. wissen. Zool. 

xxxv. p. 282. 
" Uber die systematische Stellung von Balanoglossus," Zoologischer 

Anzeiger, pp. 139, 153. 

1881. " Zur Lehre iiber die intracellulare Verdauung niederer Tiere," 

Zoologischer Anzeiger, p. 310. 
Vergleichend-embryologische Studien : 

1. Entodermbildung bei Geryoniden. 

2. " ftber einige Studien der Cunina," Zeit. f. wissen. Zool. xxxvi. 

p. 433. 

1882. 3. "t)ber die Gastrula einiger Metazoen," Zeit. f. wissen. Zool. 

xxxvii. p. 286. 

" Die Embryologie von Planaria polychroa," Zeit. f. wissen. Zool. 
xxxviii. 3, p. 331. 

1883. " Untersuchungen iiber die intracellulare Verdauung bei wirbellosen 

Tieren," Arbeiten d. zool. Instituts zu Wien, v. 2, p. 14 
(Quarterly Journal of Micr. Science, vol. 93). 

" Untersuchung iiber die mesodermalen Phagocyten einiger Wirbel- 
tiere," Biologisch. Centralblatt, No. 18, p. 560, Bd. iii. 

1884. " Embryologische Mitteilungen iiber Echinodermen," Zoologischer 

Anzeiger, vii. Nos. 158, 159. 
" t)ber eine Sprosspilzkrankheit der Daphnien ; Beitrag zur Lehre 

iiber den Kampf der Phagocyten gegen Krankheitserreger," 

Virchow's Archiv, vol. 96, p. 177. 
" t)ber die Beziehung der Phagocyten zu Milzbrandbacillen," 

Virchow's Archiv, vol. 97, p. 502. 
" Uber die pathologische Bedeutung der intracellularen Verdauung," 

Fortschritte der Medizin, 1884, p. 558, No. 17. 

1885. Vergleichend-embryologische Studien : 

4. " tJber die Gastrulation und Mesodermbildung der Ctenophoren, 


5. " tJber die Bildung der Wanderzellen bei Asterien und Echiniden," 
Zeit. f. wissen. Zool. xlii. p. 656. 

1886. " Medusologiache Mittheilungen," Arbeiten d. zool. Institute zu 

Wien, vi. 2, p. 1. 

Embryologische Studien an Medusen, ein Beitrag zur Genealogie 
der Primitivorgane, Wien, 1886. 

1887. " Sur 1' attenuation des bacteridies charbonneuses dans le sang des 

moutons refractaires," Annales de 1'Institut Pasteur, i. p. 42, 

No. 1. 
" tJber den Kampf der Zellen gegen Erysipelkokken, ein Beitrag 

zur Phagocytenlehre," Virchow's Archiv, vol. 107, p. 209. 
" t)ber den Phagocytenkampf bei Ruckfalltyphus," Virchow's 

Archiv, vol. 109, p. 176. 
"Sur la lutte des cellules de 1'organisme centre 1'invasion des 

microbes," Annales de 1'Institut Pasteur, i. p. 321, No. 7. 
" Kritische Bemerkungen iiber den Aufsatz des Hernn. Christmas- 

Direkinck - Holmfeld, I. V.," Fortschritte der Medizin, 17, 

p. 541. 

1888. " tJber die phagocytare Rolle der Tuberkelriesenzellen," Virchow's 

Archiv, vol. 113, p. 63. 
" Pasteuria Ramosa, un representant des bact^ries a division longi- 

..tudinale," Annales de 1'Institut Pasteur, p. 165, t. ii. No. 4. 
" fiber das Verhalten der Milzbrandbakterien im Organismus," 

Virchow's Archiv, vol. 114, p. 465. 
"Reponse a la critique de M. Weigert au sujet des cellules 

geantes de la tuberculose," Annales de 1'Institut Pasteur, ii. 

p. 604. 

1889. " Recherches sur la digestion intracellulaire," Annales de 1'Institut 

Pasteur, iii. p. 25, No. 1. 
" Contribution a 1'etude du pleomorphisme des bacteries," Annales 

de 1'Institut Pasteur, iii. p. 61, No. 2. 
"Note sur le pleomorphisme, etc.," Annales de 1'Institut Pasteur, 

iii. p. 265, No. 5. 
Studies on Immunity : 
1. " Immunite des lapins contre le bacille du rouget des pores," 

Annales de 1'Institut Pasteur, iii. p. 289, No. 6. 

1890. 2. " Le Charbon des pigeons," Annales de 1'Institut Pasteur, iv. 

p. 65, No. 2. 

3. " Le Charbon des rats blancs," Annales de 1'Institut Pasteur, 
iv. p. 193, No. 4. 

1891. 4. "L'Immunite' des cobayes vaccines contre le Vibrio Metchnikowi," 

Annales de 1'Institut Pasteur, v. p. 465, No. 8. 

" Sur la propriete bactericide du sang de rat " (in collaboration with 
Dr. Roux), No. 8. 

" Recherches sur 1'accoutumance aux produits microbiens " (in 
collaboration with Dr. Roudenko), Annales de 1'Institut Pas- 
teur, v. p. 567, No. 9. 

" Beitrage zur vergleichenden Pathologie der Entzxindung," Virchow 
Festschrift, vol. 11. 

1892. "La Phagooytose musculaire " (in collaboration with Dr. Sou- 

dakevitch), Annales de 1'Institut Pasteur, vi. p. 1. 
Le9ons sur la pathologic compare* de rinflammation. Paris, 1892. 
" On Aqueous Humour, Micro-organisms and Immunity," Journal 

of Pathology, i. 


Studies on Immunity : 

5. " Immunite des lapins vaccines centre le microbe du Hogcholera," 

Annales de 1'Institut Pasteur, vi. p. 189, No. 5. 
" Atrophie des muscles pendant la transformation des batraciens," 

Annales de 1'Institut Pasteur, vi. No. 1. 
" Note au sujet du memoire de M. Soudakevitch (Parasitisme in- 

tracellulaire des neoplasmes cancereux)," No. 3. 
" tfber Muskelphagocytose," Centralblatt fiir Bakteriologie, 1892. 
" La Lutte pour 1'existence entre les diverses parties de 1'organisme," 

Revue scientifique, 10 sept. 1892, No. 11. 

1893. " Recherches sur le cholera et les vibrions, l er memoire " (Sur la 

propriete preventive du sang humain vis-a-vis du vibrion de 

Koch), Annales de 1'Institut Pasteur, vii. p. 403, No. 5. 
2. " Memoire," idem (Sur la propriete pathogene des vibrions), 

tome vii. p. 562, No. 7. 
Comparative Pathology of Inflammation. Lectures at the Pasteur 

Institute. Paul: London, 1893. 8vo. (The name of the 

translator is not stated. ) 

1894. 3. "Memoire," idem (Sur la vaccination artificielle du vibrion 

cholerique), Annales de 1'Institut Pasteur, viii. p. 257, No. 5. 
4. " Memoire," idem (Sur 1'immunite et la receptivite vis-a-vis du 

cholera intestinal), tome viii. p. 529, No. 8. 
" L'etat actuel de la question de I'immunite " (Rapport du Congres 

international de Budapest), Annales de 1'Institut Pasteur, viii. 

p. 706, No. 10. 

1895. Studies on Immunity : 

6. ' ' Sur la destruction extracellulaire des bact6ries dans rorganisme," 

Annales de I'lnstitut Pasteur, ix. p. 433, No. 6. 

1896. " Toxine et antitoxine choleriques " (in collaboration with Drs. Roux 

and Salimbeni), Annales de 1'Institut Pasteur, x. p. 25, No. 5. 
" Quelques remarques a propos de 1'article de Gabritchevsky sur la 

fievre recurrente," Annales de I'lnstitut Pasteur, x. No. 11 
Recherches sur V influence de Vorganisme sur les toxines : 

1897. 1st Memoir. " Recherches sur 1'influence de 1'organisme sur les 

toxines," Annales de I'lnstitut Pasteur, xi. p. 801. 

"Reponse a M. Gabritchevsky," Annales de I'lnstitut Pasteur, 
xi. No. 3. 

" Immunitat," Weyl's Handbuch der Hygiene. lena, 1897. 

" Recherches sur 1'influence de 1'organisme sur les toxines " (Com- 
munication faite au congres de Moscou en aout 1897), Annales 
de I'lnstitut Pasteur, xi. No. 10. 

1898. 2nd Memoir. "Influence du systeme nerveux sur la toxine 

tetanique," Annales de I'lnstitut Pasteur, xii. No. 2, p. 81. 
3rd Memoir. " Toxine tetanique et leucocytes," Annales de 
1'Institut Pasteur, xii. No. 4, p. 263. 

1899. "Resorption des cellules," Annales de 1'Institut Pasteur, xiii. 

No. 10, p. 737. 

1900. Researches on the Influence of the Organism on Toxins : 

4eme memoire. " Sur la spermotoxine et I'antispermotoxine," 

Annales de I'lnstitut Pasteur, xiv. p. 5. 
"Sur les cytotoxines," .Annales de 1'Institut Pasteur, xiv. No. 6. 

p. 369. 
" Recherches sur 1'action de 1'hemotoxine sur 1'homme," Annales 

de I'lnstitut Pasteur, xiv. No. 6, p. 402. 


1901. Biological Studies on Old Age : 

1st Memoir. " Sur le blanchiment des cheveux et des poils," 

Annales de 1'Institut Pasteur, xv. No. 12, p. 865. 
L'Immunite dans les maladies infectieuses. Paris, 1901. 

1902. Biological Studies on Old Age. " Recherches sur la vieillesse des 

perroquets " (in collaboration with Drs. Mesnil and Weinberg), 
Annales de 1'Institut Pasteur, xvi. No. 12. 

The Nature of Man. Studies in optimistic philosophy. The English 
translation by P. Chalmers Mitchell. Heinemann : London ; 
Putnams : New York, 1903. 8vo. 

1903. Studies on Human Nature : Paris, 1903. 

Etudes experimentales sur la syphilis (in collaboration with Dr. 

Roux) : 
1st Memoir. Annales de 1'Institut Pasteur, xvii. No. 12, p. 809. 

1904. 2nd Memoir, "Eludes experimentales sur la syphilis" (in col- 

laboration with Dr. Roux), Annales de 1'Institut Pasteur, xviii. 
No. 1, p. 1. 
3rd Memoir. Id. No. 11. 

1905. 4th Memoir. Id. Annales de 1'Institut Pasteur, xix. No. 11. 
Immunity in Infective Diseases. Translated from the French by 

F. G. Binnie. University Press : Cambridge ; The Macmillan 
Co. : New York, 1905. 8vo. 

1906. 5th Memoir. Id., Annales de PInstitut Pasteur, xx. No. 10. 

The New Hygiene : three lectures on the prevention of infectious 
diseases. Translated and a preface written by E. Ray Lankester. 
Heinemann : London, 1906. 8vo. 

[Another edition.] Chicago Medical Book Co. : Chicago, 1906. 8vo. 

1907. [Another edition.] W. T. Keener & Co. : Chicago, 1907. 8vo. 
"Sur la prophylaxie de la syphilis" (Paper read at the Xllth 

International Congress in Berlin), Annales de 1'Institut Pasteur, 
xxi. No. 10. 

The Prolongation of Life: optimistic studies. The English trans- 
lation edited by P. Chalmers Mitchell. Heinemann: London, 
1907. 8vo. 

Essais optimistes. 

1908. "Eludes sur la flore intestinale," "Putrefaction intestinale," 

Annales de 1'Institut Pasteur, xxii. No. 12. 

1909. Idem. " Roussettes et microbes" (in collaboration with MM. 

Weinberg, Pozersky, Distaso, Berthelot), Annales de 1'Institut 
Pasteur, xxiii. No. 12. 

Notes on Sour Milk and other Methods of administering Selected 
Lactic Germs in Intestinal Bacterio-therapy. J. Bale, Sons & 
Co. : London, 1909. 8vo. 

1910. Idem. " Poisons intestinaux et scleroses," Annales de 1'Institut 

Pasteur, xxiv. No. 10. 

The Prolongation of Life. New and revised edition. Heinemann : 
London ; Putnams : New York, 1910. 8vo. 

1911. " Sur la fievre typholde experimentale " (Metchnikoff et Besredka), 

Annales de 1'Institut Pasteur, xxv. No. 3. 
Annales de 1'Institut Pasteur : 
Tome xxv. No. 6. Quelques remarques sur la vaccination a propos 

du memoire de M. Choukevitch sur le cholera. 
Tome xxv. No. 6. Reponse de MM. Metchnikoff et Besredka a 

M. le Dr. Vincent (remarques sur la vaccination antityphique). 



Tome xxv. No. 11. El. Metchnikoff, E. Burnet et L. Tarassevitch, 
" Recherches sur 1'epidemiologie de la tuberculose dans les steppes 

Tome xxv. No. 12. El. Metchnikoff et A. Besredka, " Des vaccina 

tions antityphiques (2nd Memoir)." 

1912. Tome xxvi. No. 11. El. Metchnikoff et Bug. Wollman, "Sur 

quelquesessaisde desintoxication intestinale," " BactSriotherapie 

The Warfare against Tuberculosis being the Priestley Lecture 
of the National Health Society for the year 1912. Published 
in Bedrock, January 1913. Constable : London. 

1913. Etudes sur la flore intestinale. 

Tome xxvii. No. 8. " Des vaccinations antityphiques " (El. Metchni- 
koff et A. Besredka). 

Tome xxvii. No. 11. " Toxicite des sulfoconjugues de la serie 

1914. Tome xxviii. No. 2. " Eludes sur la flore intestinale "(4emememoire). 
" Les diarrhees des nourrissons." 

1915. Tome xxix. No. 8. " Causerie de El. Metchnikoff a 1'occasion de 

son jubile." 

Tome xxix. No. 10. " La Mort du papillon du murier." 
" Founders of Modern Medicine : Pasteur, Lister, Koch " in Russian 

(a French translation to appear shortly). 

1916-16. " Introduction a ' Eludes sur la fonction sexuelle ' " (posthume, 
dans Le Mercure de France, 1917). 

1916. The Nature of Man. Popular edition. Heinemann : London, 

1916. 8vo. 

Note. Sources consulted : British Museum Catalogue ; English Catalogue ; 
American Catalogue. 


Accelomata, development of, 73 

Albaran, Dr., 231 

Alexander L, Tsar of Russia, 26 

Alexander II., 28 ; assassination of, 
101, 104, 218 

Alexis Michailovitch, Tsar, sends 
Spatar on mission to China, 24 ; 
death of, 25 

Alhambra, the, 124 

Amour (Amur) river, Spatar's ex- 
ploration of, 24 

Anisoplia austriaca, experiments on, 

Annales de Vlnstitut Pasteur, 1915, 
249-50 . 

Anthrax vaccine experiment, un- 
fortunate result of, 133-4 

Anthropoid apes, Metchnikofl's de- 
sire to experiment with, 140, 189 ; 
syphilis experiments with, 190, 
191 ; infantile cholera experi- 
ments with, 207, 220 ; typhoid 
fever experiments with, 207 

Antitoxins, Metchnikoff's experi- 
ments with, 162 

Arbeiten des zool. Inst. zu Wien, pub- 
lication of Metchnikoff's " Unter- 
suchung iiber die intracellulare 
Verdauung bei wirbellosen Tier- 
en," 119 n. 

Arterio-sclerosis, 189, 206 

Ascidia, Metchnikoff's difference 
with Kovalevsky re, 62, 73 

Asiatic cholera, 220 

Astrakhan steppes, 84, 85 

Austria, declaration of war on Serbia, 
1914, 240 

Baer, Prof., and Baer Prize, 58 
Bakounine, 52, 56 
Bardach, Dr., 127, 133 
Bassarab, Constantino, 24 
Baumgarten, Prof., hostile criticism 

of phagocyte theory, 126, 129 ; 

criticism refuted, 148 

Behring, theory of immunity, 148 ; 

discovery of antitoxins, 149, 150 
Beketoff, Prof., 40, 58 
Bell, the, 29 

Berlin Congress, 1890, 148-9 
Berthelot, M., pupil and collaborator 

of Metchnikoff, 197, 221 
Besredka, Dr., researches, 161-2, 


Birsch, 169 n. 
Bobrinsky, Count, 111, 112 
Bogomoloff, 29 
Bombyx mori (moth of the silk-worm), 

Metchnikoff's experiments with, 

238-9, 251 
Bordet, M. I., important researches 

and experiments, 165 
Borrel, M., 162 

Brockhaus and Effrone, Encyclo- 
paedia quoted, 25-6 
Brone, Classes and Orders of the 

Animal Kingdom, 31 
Biichner, 169, 265 ; paper on humoral 

theory, 150 

Buckle, History of Civilisation, 29 
Buda-Pest Congress (International, 

1894), 159 
Bulletin of the Moscow Society of 

Naturalists, 33 
Bunsen, 48 
Burnet, M., 211 

Caillaux affair, 240 

Cantemir, Prince, 26 

Casso, Minister of Public Instruction, 

Cephalopoda, Metchnikoff's study 

of, 56, 57 
Chamberland, 265 
Chauveau, 169 and n. 
Cholera outbreak in France, 1892, 

154 ; Metchnikoff's experiments 

with cholera vibrio, 154-7, 158 

Choukevitch, Dr., 212 




Cienkovsky, friendship for and 
interest in Metchnikoff, 59, 60, 
73 ; resigns from Odessa Uni- 
versity, 75 ; bacillus, 210 

Clauss, Prof., 48, 119 

Coelentera and intracellular diges- 
tion, 107, 110, 116 

Ccelomata, development of, 73 

Cohendy, M., research work of, 

Cohn, association with and interest 
in Metchnikoff, 43, 45 

" Conception of Nature and of 
Medical Science, A," Metchnikoff's 
Stuttgart Lecture, 1909, 209, 224 

Crimea, and Black Sea fauna, 59 

Ctenophora, 73 

" Curative Forces of the Organism, 
The," Metchnikoff Lecture on, 
in Berlin, 1908, 208, 223 

Curded milk, manufacture, Metchni- 
koff's connection with, 226-7 

Daphnise, experiments with, 121, 


Darre, Dr., 256, 266, 271 
Darwin, The Origin of Species, 41 ; 

theories, 276, 277 
Diabetes, 246 

Dubois-Reymond, journal of, 48 
Duclaux, M., 137, 265 
Duniasha (AvdotiaMaximovna),4, 10 

Eberth's bacillus, 207-8 

Echinodermata, Metchnikoff's re- 
searches, etc., 61, 62, 70; meta- 
morphoses of, 72, 73; and intra- 
cellular digestion, 107, 110, 116; 
observations on larvae transforma- 
tion, 119 

Education from an Anthropological 
Point of View, Metchnikoff's paper 
on, 63, 74 

Ehrlich, Prof., 199, 265 

Embryology, comparative, Metchni- 
koff's studies in, 50-51, 56, 57, 107, 

Emmerich, 265 ; attack on phagocyte 
theory, 131 ; attacks refuted, 148 

Engelmann, 45 

Ephemeridse, Metchnikoff's study of, 
105, 106, 193, 237 

Escherich, 265 

Essais optimistes, 191-2, 209 

Etudes sur la nature humaine, 185, 
191, 209 ; quoted, 188 

Evolution, Metchnikoff's researches 
in, 50-51 

Fabricia, Metchnikoff's researches 
on, 43 

Fedorovitch, Mile. Ludmilla, after- 
wards Madame Elie Metchnikoff, 
63 ; engagement to Metchnikoff, 
65-9 ; marriage to Metchnikoff, 
69 ; illness of, 69-70 ; a clever 
draughtswoman, 71 ; temporary 
recovery of, 73 ; relapse, 74, 75, 
78; death, 79 

Fedorovitch, Mile., 71, 74, 78, 80; 
account of interview with Metchni- 
koff, 83 

" Flora of the Human Body," 
Wilde Lecture, 1901, 182 

Flore du corps humain, La, 224 

" Forces curatives de 1'organisme," 
quoted, 120-21 

Forty Years' Search for a Rational 
Conception of Life, 223 

Founders of Modern Medicine, The, 
extract from preface to, 247-8 

Fraenkel, Carl, 265 

Gamaleia, Dr., 127, 133 

Garibaldi Movement, the, 47 

Gamier, M., 21, 22 

Gastrcea, Haeckel's theory of the, 108 

" Gastrotricha," Metchnikoff's es- 
tablishment of, 42 

Geneva, young revolutionary centre, 

Oeodesmus bilineatus, 106-7 

Geophilus (see Myriapoda) 

George, Henry, 202 

Germany, Metchnikoff's apprecia- 
tion of scientists of, 55 

Germany, declaration of war on 
Russia, 240 ; on France, 242 

Giessen, Naturalists' Congress at, 
1864, 44-5 

Glycobacter peptonicus, 221, 222 

Goethe, Faust, 195, 204 

Goldschmidt, Dr., 78, 79 

Gottingen News, Leuckart's memoir 
on Nematodes in, 48 

Granada, 124 

Gravitz, 169 n. 

Grove, The Unity of Physical Forces, 

Guancios, Caves of the, 77 

Haeckel, theory of the gastrcea, 108 

Hayem, 169 n. 

Heitz, Dr., 231 

Heligoland, flora and fauna of, 43 

Helmholtz, 48 

Henle, Prof., 54 



Herzen, Passe et pensees, 47 
Hirschfeld, 169 n. 
Hodounof, 19, 20, 22 
Hueppe, Prof., 131 
Hugo, Victor, 260 n. 

lamanouchi, M., 211 

Immunity, 122 ; opposing theories 

of Behring and Metchnikoff, 148, 

149, 150, 151; ancient and 

modern theories of, 168-70 ; 

Metchnikoff 's exposition of, 171- 


Immunity in Infectious Diseases, 170 
Infantile cholera, 207, 220-21 
Inflammation, Metchnikoff's lectures 

on, 152-3 
Intestinal flora, problem of, 196-8, 

206; further researches, 220, 

235, 280 ; experiments with rats, 

221, 222 
Intracellular digestion, Metchnikoff's 

studies of, 57, 105, 107, 110, 116, 

170, 277, 278 

Jaures, assassination of, 240 

Jelly-fish, Metchnikoff's monograph 
on embryology of, 126 

Jenner and method of antivariolic 
vaccination, 168 

Journal de Moscou, Elie Metchni- 
koff's first publication in, 33 

Jupille, M., 155 

Kalmuk steppes, Metchnikoff's 
journey to, 82-3 ; description of, 
215-16 ; Metchnikoff's anthropo- 
logical work among natives of, 
84-5 ; liability of natives to 
tuberculosis, 210-11 ; Pasteur In- 
stitute expedition to, 212 ; descrip- 
tion of, 215-17 

Keferstein, Prof., 54 

Kent, Saville, discoveries of Proto- 
spongia, 110 

Kharkoff, 1,1 6,20; Lycee, progress in, 
28 ; University, ancient methods 
in, 31-2, 37, 40 

Kherson, peasants' grievances and 
vexatious conduct in, 113, 114 

Kirghiz steppes, endemic plague in, 
211 ; Russian plague mission to, 
211, 215, 218; description of, 214 

Kleinenberg, Prof., encouragement 
of Metchnikoff, 118, 119 

Kleps, 169 n. 

Koch, Prof., 265; attitude to 
Metchnikoff's theory, 133, 149 

Kolliker, Prof., 37 

Kovalevsky, Alexander, friendship 
with Metchnikoff, 49, 58 ; work of, 
51,52,61, 62, 72, 73, 108 ; divides 
Baer Prize with Metchnikoff, 58 

Kriloff, 26 

Kiihne, 41 

Latapie, M., 155 

Law of Life, The, 223 

Lemons sur la pathologie comparee de 

Vinflammation, 152-3 
Leube, Dr., 231 
Leuckart, Prof., 43-5, 46 
Lilienfiorse, 199 
Lister, Dr., 148 
Loeffler, 265 

London Congress, 149-50 
Lubarsch, attacks on Metchnikoff's 

theory, 232 
Lucernaria, 73 

Macaques or Barbary apes, 124 ; 
Metchnikoff's typhoid experi- 
ments with, 207-8 

Macrophages, 163-4, 166, 178, 184 

Madeira, 75 

Maeterlinck, Maurice, 228-9 

Maisonneuve, M., 191 

Malaga, gardens of, 124 

Manoukhine, Dr., 231 

Martin, Dr., 256, 273 

Medusa?, 72, 73, 116 

Mertens, 76, 79 

Messenger of Europe, Metchnikoff's 
contributions to, 208-9, 239 n. 

Messina, Metchnikoff's work at, 61 

Messina, the Metchnikoff home at, 

Messina, earthquake at, 1908, 115, 116 

Metazoa, 277 

Metchnikoff, Dmitri Ivanovitch, 
devotion to his brother's family, 
5, 17, 21, 28 ; appearance and 
character, 5-6 ; other references, 
12, 14 

Metchnikoff, Elie (or Ilia), parents' 
home at Panassovka, 1-3 ; birth 
of, 3 ; appearance and disposition 
in childhood, 8-11 ; early indica- 
tions of unusual intelligence, 9, 
16, 20 ; an adventurous journey 
to Slaviansk, 12-15; life at 
Kharkoff, 16-18 ; develops natural 
history tastes with Hodounoff, 
20-22; ancestry, 23-7; entry 
into and progress at Kharkoff 
Lycee, 28-34 ; friendships and their 


influence, with Bogomoloff, 29, 
with Tchelkoff, 32-3, 42, with 
Kovalevsky, 48 seq., with Cien- 
kovsky, 59-60, with Kleinenberg, 
Virchow, and others, 118-19, with 
Pasteur, 132 seq., various, 56, 
58-9, 63, 65, 93, 137; adopts 
atheism and shows continued 
interest in natural history, 29-30 ; 
love of music, 31, 34, 54-5, 93; 
plans a scientific career, 31 ; early 
publications, 33, 41 ; devotion to 
his mother, 35, 93-4 ; early love 
affairs, 35-6 ; abortive journey to 
Wiirzburg, 37-9 ; at Kharkoff 
University, 40-42; an early con- 
troversy with Kuhne, 41 ; in- 
fluenced by Darwin, 41, 50 ; early 
researches and privations in Heli- 
goland, 43-5 ; letters to his mother 
quoted, 44-6, 65-9 ; at Giessen 
Congress, 45 ; work and relations 
with Leuckart, 45-8 ; eyesight 
troubles, 46, 62, 82-3, 105 ; visit 
to Geneva, 46-8 ; researches, 
Mediterranean, 48-53, 56-7, 61 
seq., in the Crimea, 59-60, at 
Spezzia, etc., 70-73, anthropo- 
logical among Kalmuks, 84-5, in 
intracellular digestion and Ephe- 
meridse, 105-11, 116, in infectious 
diseases, 128, in tuberculosis and 
phagocytosis, 133 ; at Pasteur 
Institute, 135-6, in cholera, 154- 
157, in immunity, 168-80, in 
senile atrophies and intestinal flora, 
182-9, 191, 196-8, 206-8, 220 seq., 
in syphilis, 189-91, in infantile 
cholera and typhoid, 207-8, 220, 
in tuberculosis and plague among 
Kalmuks, 210-19; silk - worm 
moth, 238-9, 251 ; contribution to 
foundation of comparative em- 
bryology, 51, 56 ; studies in 
Germany and opinion of German 
scientists, 54-5, 57 ; illnesses, 55- 
56, 65, 104, 181, 217, 222, 229 seq., 
249 ; return to Russia and Odessa 
University appointment, 58-60 ; 
appointed Zoology Professor at 
Petersburg, 61 ; interest in edu- 
cational questions, 63, 100; life 
at Petersburg, 63-4, 71 seq. ; 
engagement and first marriage, 
66-70; reappointed to Odessa 
University and difficulties of 
appointment, 73, 75, 78, 98 seq. ; 
his philosophical theory and its 

evolution, 74-7, 184-9, 191-5, 209, 
222-4, 228-9, 281-3 ; visit to and 
life at Madeira, 75-7; death of first 
wife, 79 ; attempts suicide, 80-81 ; 
Mile. Fedorovitch's description of, 
83 ; journey to Astrakhan steppes, 
82-3 ; studies of childhood, 86 ; 
meeting with family of second 
wife and growing intimacy, 86-8, 
94, Setchenoffs description of, 
88 ; harmony of second marriage, 
89-95 ; character and disposition, 
96-8, 143-5 ; views of women's 
scientific capacity, 103 ; inocu- 
lates himself with relapsing fever, 
104 ; and the phagocyte theory, 
first statement of, 110, describes 
first inception of, 116-17, pro- 
gress in, 117-22, 126, 128, 142, 
148, 150-53, 158-66, 183, 208-9, 
controversies and attacks on, 
131, 133, 142, 147-9; difficulties 
over Russian estate manage- 
ment, 112-14 ; life at Messina, 
115-19; again returns to Russia, 
119; journey through Spain to 
Tangiers, 123-4 ; life at Tangiers 
and Villefranche, 125-6 ; describes 
work at Bacteriological Institute, 
Odessa, 127-8 ; describes first 
meeting with Pasteur, 132 ; 
Pasteur's offer, 132; visit to 
Berlin and reception by German 
scientists, 133 ; work and in- 
fluence at Pasteur Institute, 135- 
146 ; M. Roux's appreciations of, 
138-9, 150, Ij59 ; other apprecia- 
tions, 141, 165 ; life at Sevres and 
Paris, 144-5 ; visit to England, 
149 ; triumph at London Con- 
gress, 150 ; interest in Pfeiffer's 
phenomenon, 158-60 ; theory and 
studies of natural death, 192-5, 
230-35, 237-8, 252 ; receives Nobel 
Prize, 199 ; journey to Sweden 
and Russia, 199-200; visit to 
Tolstoi, 200-205 ; expedition to 
Kalmuk steppes, 210 seq. ; un- 
pleasant incident of lacto-bacilli 
fabrication, 225-7 ; kindness to 
friends, 227-8 ; descriptions of 
his own symptoms, etc., 229-36, 
250-51, 263-5; holidays at St. 
Leger - en - Yvelines, 228, 237-9, 
251 ; effect of war on, 239-46, 261 ; 
preface to Founders of Modern 
Medicine quoted, 247-8 ; plans 
a work on sexual questions, 249, 



252, 260; jubilee celebrations, 
249-50 ; last illness, 254-73 ; last 
days at Pasteur Institute, 256-73 ; 
death, 273 ; synopsis of work and 
achievements, 276-81 

Metchnikoff, Madame, meeting with 
Metchnikoff, 87, parents and 
family, 87-8, 94, marriage, 89, 
90, relations between husband 
and wife, 90-95, illness of, in 
1880, 104, loss of both parents, 
112, illnesses of, 123, 181, 252 

Metchnikoff, Emilia Lvovna (nee 
Nevahovna), appearance and dis- 
position, 2, 5, 6, 93; a capable 
housewife, 3 ; a devoted mother, 
4, 6, 13, 14, 18, 37 ; delicacy of, 
22 ; ancestors, 26 ; influence on 
Elie Metchnikoff's choice of a 
career, 41 ; endeavours to prevent 
Elie's first marriage, 66 ; letters 
to, from Elie quoted, 44-5, 65-69 ; 
death of, 94 

Metchnikoff, Elena Samoilovna, 
4, 8, 10 

Metchnikoff, Ilia Ivanovitch, home 
at Panassovka, 1, appearance 
and character, 2, marriage, 2, easy- 
going temperament, and extrava- 
gance, 2-6, attitude to his family 
and servants, 6-7 

Metchnikoff, Ivan, 3, 8 

Metchnikoff, Katia, appearance and 
character, 8, marriage, 16, 21, 
other references, 12, 14 

Metchnikoff, Leo, 3, 8, illness of, 
19, gifted but superficial nature 
of, 19, 46-7 ; activities in Geneva 
and connection with Garibaldi 
Movement, 46-7, 80 

Metchnikoff, Nicholas, birth of, 3 ; 
appearance, 8 ; his great-aunt's 
favourite, 8, 10 ; boyhood pur- 
suits, 17-18; enters Kharkoff 
Lycee, 28 ; life in Kharkoff, 31 ; 
death of, 230 

Microphagw, 163-4, 166 

Morosoffs, the, of Moscow, 189 

Moscow, Anthropological Society of, 
Metchnikoff's report to, 85 

Moscow, International Congress, 
1897, 164-5; Skin Disease Re- 
search Society, 189 

Miiller, Fritz, Far Darwin, 50 

Muller's Archives, Metchnikoff's 
memoir on the Vorticella in, 41 

Myriapoda, embryology of, 76, I 

Naegeli, 169 n. 

Naples, cholera epidemic in, 1865, 
53; Metchnikoff's first stay at, 
49-53, second stay, 62 

Napoleon, 260 n. 

Natural death, Metchnikoff's studies 
of, 237, 280-81 

Natural science, Metchnikoff's cam- 
paign for the teaching of, 100 

Nematodes, Metchnikoff's dis- 
coveries, etc., 42, 46 

Nevahovitch, Leo, 26 

Nicholas I., 28 

Nobel Prize, the, 199 

Nocard, M., 265; appreciation of 
Metchnikoff, 165 

Norden, Dr., 231 

Odessa, University of, 58-9, Metch- 
nikoff's work at, 60-61, 98-9, 
party intrigues at, 75, 101, rights 
to autonomy threatened, 101-3, 
Congress, 1883, 120, bacteriologi- 
cal Institute founded at, 127 

Oldenburg, Prince of, 129 

Panassovka, the home of the 
Metchnikoff s, 1, 3, fire at, 20-21 

Parenchymella, explanation of, 109- 

Paris, International Congress, 1900, 

Paris, air raids on, 246 

Pasteur, antirabic inoculations, 127, 
Metchnikoff's first interview with, 
132, friendship with Metchnikoff 
and interest in phagocyte theory, 
137, experiments in vaccination 
andimmunity, 168-9, death of, 181, 
discovery of lactic fermentation 
microbe, 193, age at death, 265 

Pasteur Institute, the, 132, Metch- 
nikoff's work and influence at, 134- 
142, 144, Metchnikoff's apprecia- 
tion of, 139, effect of outbreak of 
European War on, 244-5 ; celebra- 
tion of Metchnikoff's jubilee, 249 

Peter the Great, Tsar of Russia, 24, 

Petersburg, 2, 19, Congress of 
Russian Naturalists at, 1867,60-61, 
difficult conditions of Metchni- 
koff's work at, 63-4, 71, foundation 
of Bacteriological Institute at, 

Petersburg Geographical Society, 82 

Petrushka, 4, 12, 13 



Pettenkoffer, 154, 236 
Pfeiffer, 265, experiments in extra- 
cellular destruction of microbes, 
158-60, 165-6, 175; attacks on 
Metchnikoff's theory, 232 
Phagocytella, 110, 126 

Phagocytes, origin of Metchnikoff's 
theory of, 51, 57, 278, develop- 
ment of theory, 110, 111, 113, 
120-22, 142, inception of theory, 
116-19, Baumgarten's hostile 
criticism of theory, 126 ; applica- 
tion of theory to erysipelas, 128, 
opposition to theory, 131, 151, 
controversy, 148, renewed ex- 
periments for proving theory, 148, 
149, 150, 151, 152, 153, 279; 
vindication of, at Buda-Pest Con- 
gress, 159, 160 ; experiments 
with toxins and poisons, 160-62; 
experiments with antitoxins, 162- 
164, and doctrine of immunity, 
170-80, and senility, 183, 280 ' 

Phagocytosis, Metchnikoff's first 
paper on, read at Odessa Congress 
of Physicians and Naturalists, 
1883, 120 

Phyllirhoe, 175 

Picot, E., Chronicle of John Neculua 
quoted, 23 

Pirquet's test, 211 

Pleomorphism of Microbes, Metchni- 
koff's memoir, 1888, 211 

Poland, Revolution in, 1830, 26 

Polypi, 72 

Popular Star, 29 

Preyer, theory of fatigue and sleep, 

Protospongia, discovery of, by Saville 
Kent, 110 

Pushkin, 2, 26 

Radlkoffer, The Crystals of Proteic 
Substances, 33 

Rasputin, 219 

Recklinghausen, 169 n. 

Relapsing fever, experiments to 
prove phagocytic reaction, 129 

Renon, Dr., 255 

Rotifera, 193, 237-8 

Rousseau, J. J., Confessions and the 
Nouvelk Heloise, 260 n. 

Roux, Dr., 137, 255, appreciation 
of Metchnikoff quoted, 138-9, 
141, 159, 249 ; collaboration with 
Metchnikoff, 150, 162, 163, 164, 
wins Osiris Prize, 189 ; reply to 
campaign against Metchnikoff, 

226 ; friendship with and visits to 
Metchnikoff in his last illness, 
257, 267, 273 
Rubenstein, M., 260 

St. Leger-en-Yvelines, 228, 237 

Salimbeni, Dr., 163, 184, 211, 215, 
256, 266, 272-3 

Sanarelli, Dr., discovery of choleri- 
form bacilli, 156 

Sarepta, 217-18 

Schaudinn, discovery of syphilitic 
treponema, 190 

Scorpion, the, Metchnikoff's re- 
searches concerning the develop- 
ment of, 71 

Senility and death, Metchnikoff's 
views on and researches, 182-8, 

Serums, their action, 177 

Setchenoff, Prof., 52-3, 71, 73, 78, 
239 ; autobiography quoted, 88 

Sevres, Metchnikoff Villa at, 144, 145 

Siphonophora, 72 

Slaviansk, adventurous journey of 
the Metchnikoff family to, 12 

Spain, Metchnikoff 's eventful journey 
through, 80 

Spatar, Joury Stepanovitch, 26 

Spatar, Nicholas Milescu, exploits 
and adventures of, 23-4, mission 
to China, 24, literary activities 
and services to Peter the Great, 
25, death of, 25 

Spezzia, the Metchnikoffs sojourn 
at, 70-71 

Sponges and Echinodermata, Metch- 
nikoff's study of, 61, 72, 106, 117 

Stepanita, Prince, his dealings with 
Nicholas Milescu Spatar, 24 

Syphilis, Metchnikoff's researches 
on, 189-91, 280 

Tangiers, journey to, through Spain, 

123-4, description of, 124-6 
Tarassevitch, Dr., 212 
Tchistovitch, Dr., 231 
Time for Marriage, The, Metchnikoff's 

paper on, 77 
Tolstoi, Leon, a day at lasnala 

Paliana, 200-205 
Tolstoi, Countess, 203 
Tornaria, Metchnikoff's discovery 

concerning, 70 
Toxins and the phagocyte theory, 

experiments, 160 seq. 
Trattoria della harmonia, the, 53 
Trieste, Metchnikoff's work at, 62 



Tschelkoff, Prof., 32, 33, 40, 41, 42 

Tshori, Convent of, 217 

Tuberculosis, researches on phago- 
cytosis, in, 133; Metchnikoff's 
theory of natural vaccination, 
210-11, 218 

Typhoid fever, 207-8 

Vaquez, Dr., 230 
Veillon, Dr., 256 
Vienna, Hygienists' Conference at, 

1887, 131 
Villa Orotava, giant dragon-tree at, 

Virchow, cellular theory, 32, 48, 
169 n. ; encouragement of Metchni- 
koff, 118-19; Archives, publication 

of Metchnikoff's researches in, 122, 

Volga, description of, 212-13 

von Noorden, 182 

von Sieboldt, Prof., 54 

Vorticella, the, Metchnikoff's mem- 
oir on, 41 

Waldeyer, 169 n. 

Weinberg, M., 184 

Widal, Dr., 255, 256 

Wollman, pupil and collaborator of 
Metchnikoff, 196-7, 221 

Wiirzburg, University of, Metchni- 
koff's abortive journey to, 37 

Zalensky, 32 


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